Yeah, if the stickers have been on the label for over 20+ years, I'd consider leaving them alone. Granted, if you're careful and patient you can remove them, but you do indeed risk having to deal with sticker residue, which itself is a hassle to deal with. Keep in mind that not all stickers are the same, so some might be easy to remove, even without having to use anything other than your fingernails, especially considering they're 25 years old.
This is what you would do..
Get some cotton swabs, hot water, and/or rubbing alcohol - you can also consider acetone, which is what I would often use, but this would be the part where having steady hands and a crapload of patience become crucial. With the swab simply tap the sticker ever so lightly, dampening it enough while avoiding going out of its borders, reapplying whichever liquid you chose after maybe a minute. Which liquid to use would be dependent on the sticker, so I would recommend trying to peel it off to see how "weak" it is. I would often use acetone on stickers that seemed would leave residue once peeled; however, there are stickers that outright are meant to stay, so cutting your losses would be the better option. Standard price tags are usually easy to deal with, but most other types will requite the extra labor.
So yeah, in short, my main advice is to try and peel those stickers off, gently of course, to determine if it's a good idea to remove them at all.