changing my jetting

Hey fellas, i'm a true beginner when it comes to working on the big xr. I was wondering how hard it would be to change my own jetting and about how long it would take. I have all the tools needed. My '01 has a white bros t4 can on it, but other than that the engine is believed to be stock. It has oversized front brakes & renthal bars but thats about it. I was wanting a little more power out of it...maybe a few holes in the number plate over the air box, and some beter jetting. I'm in ohio and from what i can tell, a 170/68s combo would work well and apparantly i can set something on the #3 setting (any info would help). I do all trail riding/no commuting. Thanks in advance Happy new years!!!