Anyway, installing if on a 4-wheeler with all the compound angles and curves will be no fun task if you've never installed vinyl before. However, I'll give you some pointers if you're dead set on doing it yourself.
1. Before doing anything clean, clean and then clean some more. Any leftover gasoline or oil residue will eventually cause the vinyl to fail and peel off. I would give it a good powerwash to knock off any dust, mud and grime. Then after a good soapy bath of dish detergent I would wipe down everything with mineral spirits or alcohol to remove any remaining oils. *This is especially important if like many off roaders you use armor-all or something like it to keep your fenders slick and shiny.
2. Depending on how your bike is put together I would remove as many pieces as I could and wrap them individually and then re-assemble.
3. You didn't mention what type of vinyl you bought and I'm hoping for your sake it is 3M controltac or something similar. Controltac vinyl allows you to remove and reposition the vinyl time and again until firm pressure is applied to it. I'm also going to guess that this stuff isn't laminated (like most camo vinyls I've seen) which will make it feel a little thin. (I'll warn you that without lamination fading might become a problem if this bike sees a lot of outdoor sunshine.)
4. When you start cutting down the vinyl to do the individual pieces make sure you have MORE than you need. (You may need to seam pieces or overlap them in order to make the vinyl work in weird places.) Vinyl will stretch to a degree, but all those compound curves will use more material than you think. Work slowly and methodically just a few inches at a time working out all the air bubbles etc. You'll probably get some wrinkling but since this is camo it probably isn't a big deal. If you want to do it right, you'll need a heat gun or hair dryer to help warm up the vinyl to stretch around all those curvy places. Again, working slowly and patiently is key.