there are two ways to do this. the first way is which makes the major difference is the number of links in the chain. unless you have changed gearing, you need to have the OEM amount of links. although for your machine i dont know for sure, it should be in the neighborhood of 96 links. it should be in your owners manual if you have that, and if not, a service manager should be able to verify the amount of links. if you are not absolutly certain you have the correct amount of links, you need to start there. the chain may need to have a few links cut off if it is too long.
once that is squared away, this is what you do.
in the image below, you want to your machine loosen the two bolts #33 in the diagram as loose as they will go without actually taking the nut off of the bolt. you shouldnt need to, and if you can help not taking the nut off, it will make reassembly easier. once the two #33 bolts are loose
now, in the diagram below, look at #28. that is the fine chain adjustment. #28 is clamped down in the swimarm by the two bolts you just loosened. on the outside of the housing, there should be a hexagon shape built into on one side. this allows you to stick the proper size big wrench on it and rotate it. #28 is egg shaped, it is a big lobe. if you rotate the lobe (thicker section) toward the front of the quad, it moves the axle rearward, thus taking up chain slack, and vice versa, rotating the lobe to the back moves the axle forward creating more chain slack.
like i said, this is a fine adjustment, but also critical. need to verify the correct amount of links. also in your book should be chain adjustment slack, or the dealer should be able to tell you that as well. probably going to be 1/8 to 1/4 of an inch is my guess. if you tighten the chain too much, you run the risk of crushing the countershaft seal and leaking out the tranny fluid.
hope that makes since. confused or any questions just let me know