How is cannabis resin made from the marijuana plant?

The common form, hashish, is made by removing the resin glands and collecting them. The most recent method is to submerge the plant matter in a bucket of ice water. This chills the resin, and makes the glands brittle. The mixture is agitated, to break off the glands. Then, it is passed through a series of filters. Resin glands are fairly uniform in size, so the result is nearly pure glands, containing exceptionally high concentrations of cannabinoids.
This can be done without water or filters using canned butane, or some other pressurized solvent. The gas is sprayed through a tube filled with plant matter, and the tube is shaken. The butane, in liquid form, carries the active chemicals away from the plant, and then evaporates, leaving a crust of resin. Beware volatile, flammable chemicals...
One historical method was to paint someone in honey and send them running through the hemp-fields. Once the runner returned, the resin glands (and dirt, leaves, insects, etc.) stuck to the honey was scraped off.
I'm sure there are other ways, but they're all variations on the same idea.

It's extracted a few different ways.

How to make hash -

First video: cold water extraction.
Equipment:

http://www.bubblebag.com/index2.php

Second video: screen and make pressed hash.
Equipment:

http://www.everyonedoesit.com/online_headshop/productCategory.cfm?sC=Kif_Box&iProductCategoryID=132&iLastCatID=121

http://www.everyonedoesit.com/online_headshop/productCategory.cfm?sC=Pollen_Pressers&iProductCategoryID=725&iLastCatID=121

Cannabis resin is formed from glands on the plant. It is more commonly found in C. Indica, or hybrid plants with an indica dominance.

It does add to the potency of the plant. However it contains more CBD's, chemicals that give you a couch lock stone.

The resins purpose is to prevent damage from the sun, if I remember correctly.

Hashish is made from cannabinoid-rich glandular hairs known as trichomes, as well as varying amounts of cannabis flower and leaf fragments. The flowers of a mature female plant contain the most trichomes, though trichomes are found on other parts of the plant. Certain strains of cannabis are cultivated specifically for their ability to produce large amounts of trichomes. The resin reservoirs of the trichomes, sometimes erroneously called pollen, are separated from the plant through various methods. The resulting powder is compressed into blocks of hashish aided by heat, which can be easily stored and transported. Alternatively, the powder consisting of uncompressed, dry trichomes is often referred to as 'kief' instead of 'hashish'.

Mechanical separation methods use physical action to remove the trichomes from the plant. Sieving through a fine screen is a vital part of most methods. The plants may be sifted by hand or in motorized tumblers. Hash made in this way is sometimes called 'dry sift'. 'Finger hash' is produced by rolling the ripe trichome-covered flowers of the plant between the fingers, rupturing the trichomes, and collecting the freed resin that sticks to the fingers.

Ice water separation is a more modern mechanical separation method which submerges the plant's leaves in ice and water and agitates the mixture, sometimes in a Washing machine. The low temperature solidifies the resinous trichomes. They become brittle, and the mechanical agitation breaks them off the leaves. The waste plant matter, detached trichomes, and water are separated by filtering through a series of increasingly fine screens or bags (with pore sizes ranging from 220 to 25 microns). The trichomes of various sizes are then dried and pressed into solid blocks of hash. Kits are commercially available which provide a series of filter bags meant to fit inside standard bucket sizes. Hash made in this way is sometimes called 'ice hash', or 'bubble hash'. This method produces valuable product from leaf matter that would otherwise be discarded (after the plant's "buds" are trimmed for sale). The advent of this process has made hashish much more readily available in North America.

Chemical separation methods generally use a solvent such as ethanol or hexane to dissolve the lipophilic desirable resin. The remaining plant material is then filtered out of the solution and sent to the compost.The solvent is then evaporated, leaving behind the desirable resins, called honey oil, 'hash oil', or just 'oil'. Honey oil still contains waxes and essential oils and can be further purified by vacuum distillation to yield 'red oil'. The product of chemical separations is more commonly referred to as 'honey oil'.

simply, the brown hairs that you see coming out of the buds is pollen, hash. the plant is grown collected and then dried. once dry the leaves are reoved and the plant is ready for beating. this is done in a device made using a large clean bowl or container with a larg top and surface. a material like womens tights is then placed over the top and wraped around a stick underneath to allow for tightening. when taught the buds are placed over the top and then covered in plastic. the beating then begins for about 5 minutes with small ish sticks. whats left in the bowl is the best hash, double 0. the powder is then pushed together and takes form. the plants can be procesd up to three times getting all different qualities of hash. the hash sold on the streets has been compressed, after the beating, in a machine reducing the quality and oil content. the plant is then ready o be turned into gifi. basically they chop up what is left and mix 1 third cigar leaf to chopped up bud this is then smoked through a long thin pipe. th seeds can be reused or crushed up with chocolate and all sorts of pills and downers to make what they call mejune, not highly recommended as you cant predict it. to smoke the best get a flight to morrocco.

Here is how to make hash http://weed-smoking-tricks.blogspot.com/2010/01/how-to-make-hash.html from weed