I would press my thumb hard on the card resting on a flat surface and slowly roll the remnants of paper and glue into a small sticky ball - essentially rubbing it clean. It's really rough on the skin, but for such a small surface, that's what I'd do.

Check out plastic razor blades. They’re cheap and usually found at hardware or craft supply stores. They work well to scrape off old adhesives and won’t mess with anything printed on the surface

I generally recommend Goo Gone for stuff like this (NOT Goof Off!), but it may remove the original printing (it's a very light solvent).

I think the idea from other posters - WD40 and a plastic razor blade is probably the best approach. It's good at softening adhesives, and the blade won't damage anything.

WD-40. Use q-tips to scrape around the serial. Then lightly dab where the serial is. It won’t 100% remove the adhesive but will be an improvement and you’ll be asked to see through the white stuff.

Did anyone say "carefully" yet?

Mineral or baby oil.

Personally, I would try just a bit of Windex and a fingernail to start. Any other solvent has a chance of removing the printing.

Friction and stickers,

• Lightly moisten the old sticker paper, LIGHTLY!
• Wait a bit then with clean dry hands tightly grab the cart between you fingers and thumb.
• Push agenst the old sticker and rub in one dirction, lift you thumb and put it back to where you started, repeat.
• Once you have rubbed all the paper off use another sticker to dab on the surface and then pull it away, do this in small bits, DONT PRESS DOWN, just let it lightly touch then old glue the pull it off.

The idea here is to pull the old glue off with the fresh sticker. Look at the cart. at an angle to see where you still have glue.

I've done this with many things and it works well, usally, but there has been things that don't work on. Better than using solvents, oils, or alcohols that will wipe off the ink or worse yet melt the plastic.

Flat Razor blade always works for me, just be careful

Oil on q tips or cotton balls. You're going to be dabbing a little bit of oil on the adhesive and paper in order to loosen the adhesive and then rub your fingers on the paper. Try not to get any on the contacts as I'm not sure what that'll do. After the stickers are removed you can clean the whole cart with some 90% isopropyl alcohol on a rag to remove the oil.

QD electric contact cleaner

Plastic scraper or very carefully with a razor/safety blade.

isopropyl usually doesn't wipe lettering unless it was a cheap ink which I've seen for stuff like expiration date stamps. If you're unsure, just lightly dampen with water instead.

So, I tried asking this question on Reddit, and all I got back were trolls and unserious replies.

After you scrape it off, replace it with a knockoff R4 sticker lol

Homemade goo gone with coconut oil and baking soda (and citrus oil if you want the citric acid factor, but not needed)

A razor blade should get most of the physical residue off, especially if you hit it with a hair dryer. Warm adhesive is easier to scrape off than room-temperature. If you don't trust your manual dexterity, then try one of the other methods described by other commenters.