A simple job with a Phillips screwdriver — most people do it themselves, and if you'd rather not, a family member can do all four in a minute.
1. Unscrew — Loosen the single screw holding a worn foot.
2. Swap — Lift it off and press the new foot into place.
3. Tighten — Screw it back in, snug. Then repeat for the other three.
No glue, no trip to a repair shop. Do them one at a time so the others show you how the new one should sit.