IF we printed it and the material is in its serviceable life, in other words not cracking or anything, then we give a flat rate as I know the install, I know that its either Avery or 3M and will remove leaving little to no adhesive. Signed waiver is always good on a removal AND on full wrap installs. If the vinyl is in bad shape or its something some other place installed then its shop rate and if it is too horribly gone, decline. On someone elses material you can always try testing a small spot but that is not always the full picture. Got bit on that just recently. A long time customer (pro tournament fisherman) bought a used boat that had a wrap on it. Test removed a small bit and its 3M. Came off easy and wrap was in decent shape. Turns out the freaking idiot who installed it thinks you are supposed to use Primer 94 with a paint roller. Literally a 2 to 3 inch band of freaking primer along the bottom edge AND just under the rub rail! WTF??? Why on Gods green earth would you put primer up under the freaking rub rail??? its a boat, not a submarine! We do not even use any along the bottom on boats, we just add a strip of edge sealer tape (1/2 strip of clear lam) and they last 2 to 3 year just fine.