I did it. I went all out and re-stickered an old Revenge using the Hessport DIY labels (except for the white Rubik's logo square--some things haven't improved). It wasn't hard, and if you're a purist, you might find it enjoyable. Some of this is common knowledge, but I put it in anyway for tehe beefit of anyone new to this stuff
1. Remove the old stickers. You might want to do this with the cube still assembled. Either way, find the center blue label with the strange circular blister. (There are only four center blues, you'll know the one.) Unscrew and carefully remove the outer cap. One by one the pieces should come out--if you've never seen the inside of a 4x4x4, you're in for a treat. DON'T force anything while pulling out or putting back in; a little wiggle at most should do. At the end, you should have 57 black pieces, one screw and one ball mechanism.
***Be careful with the labels. You will be shocked how strong and thick the plastic is, and if you pry them up with a fingernail you might jab one into the quick. It hurts, let me tell you.
2. Get a bottle of the miracle known as Goo Gone from any hardware store or pharmacy. Whatever sticker residue remains (and there will be a bunch with a 20-year old Revenge) can be removed easily. I took my time and swabbed each piece, face and sides, to get everything squeaky clean, then washed the lot in mild dish soap and water and let them air dry. I figured if I left the cube assembled all of the residue would collect between the pieces.
3. Reassemble. This will take some practice; bottom up is usually a good idea, with the screw piece being on top. Which piece goes where shouldn't matter, but I was anal enough to put the Rubik's logo in the lower left center and the screw cubie on the lower right of the opposite face (which IIRC is correct).
4. Position the cube for sticker placement. Sort out the cube a bit so that the cubies on each face are more or less straight--this is much easier than on a 3x3x3. In order to make sure the stickers go on evenly, put the soon to be stickered face on top and turn that level 45 degrees.
***The classic sticker layout, as if no one remembers: White opposing blue, red opposing orange, green opposing yellow, with one corner showing in clockwise order white, green, and orange.
5. Stickers! They come in 4x4 grids, with standard backing as well as a clear sheet on top so you can eyeball exact placement before committing the adhesive. In the case of the white side, if you don't want the new Rubik's logo, either peel the sticker out or save it by slicing around the backing paper so you only reveal the other fifteen. Use a credit card or something similar to smooth down the stickers before removing the clear layer.
*** Check your green stickers before applying. One of the edge stickers (upper right, not the corner) has a little white on its inside edge. It's a little thing, but noticeable, and can be sliced off before or after application. Also, the red face may show some streaks after application. I'm guessing this is from the adhesive between the vinyl and clear layers.
***The new logo is on a different center piece--sorta. It looks made to go on the upper right or upper left center, instead of the lower left from the old days. You might want to cut it out and apply it "right side up" yourself.
I hope this all is of help to some of you.