If you own a soldering iron or are willing to buy one and learn how to use it, a new set of mouse switches is like <$10 and it takes a few mins to replace them. Not something you should have to do after only 4 years though. If you get a mouse with optical switches this issue will never happen.
Desoldering is definitely the hard part and I’m not experienced enough to tell you exactly how to do it, but what helped me was adding a tiny bit of leaded solder to loosen up the existing solder on the mouse. That made it way easier to wick up.