The only times I've glued (epoxied) a pad on were when the wood turned out to be so soft the screws wouldn't tighten. Strangely, this wasn't just with cheap rifles. Some of the old Sakos were like this. Getting a glued pad off was tough because I always used a band saw and had to be careful because somewhere you might find screws you didn't expect. If I had any idea screws might be involved I would cut the soft part of the pad off with large knife and look for screw heads. A band saw would usually cut through the shank of a screw but the new pad wouldn't be able to use the normal spacing for holes if they were left in the stock. If you can expose the screw heads a soldering iron held on the them can quite often soften the glue enough to break them loose and unscrew them. It's much easier with the old screws out. If I lose an eighth or a quarter of an inch of stock by cutting with a bandsaw it seldom makes much difference. If it does a spacer or a thicker pad can be installed.