Its good to get to know the ins and outs of your forks. It’ll save you loads on service costs. I always do my own, no special tools needed, just a little bit of fork oil and maybe thicker stuff for Fox’s (fluid).
For the Revs, you’ll also need a circlip plier to remove the circlip at the bottom of the inners/stanchions.
Remove lowers by letting air out, undoing the bolts at bottom of each leg. Dont remove completely at first, so you can, using a rubber mallet or wood+hammer, give the rods a whack to knock them upwards and free them. Remove bolt/nut completely and drain the bit of oil. Pull lowers off.
Guide here: http://www.bikeradar.com/gear/article/workshop-rockshox-revelation-lower-leg-service-24649/
Now get circlip pliers out and remove circlip from air damper side only. Push the rod up and rubber stopper to make it easier. Now pull rod down and remove bottom parts (cant remember which, see manual), add spacer or 2. Install parts again, and then circlip (make sure its located proper). Insert lowers and whilst there is space/no rods extending out of lowers, add 15ml/15wt fork oil using a syringe. Add bolt/nut and tighten. Jobs a goodun
http://www.freerider.ro/manuale/manual_tehnic_rock_shox_revelation.pdf