One is to replace the switches. If they're hot swappable then it's easy. If they're not, it's hard -- but easy if you're willing to spend money on a desoldering iron. Depending upon your feelings here, I would consider it maintenance to keep it going if you love it -- particularly if you use it to prevent RSI.
A quick look shows matias does sell replacement switches -- which is usually the thing to go. Springs, crud, etc end up in the switches. Sometimes you can tear them apart to fix them, sometimes it's easier to toss them and replace them.
The typical desoldering tool for keyboards is something like this:
https://www.amazon.com/ENGINEER-Engineer-Solder-Suction-SS-0...
They also have things like this that are maybe more functional than trying to do it two handed:
https://www.amazon.com/zycllycx-Electric-Automatic-Desolderi...
But the hakko is the gold standard here. If you have keyboards you absolutely love but are soldered, this is the way to go.
https://www.amazon.com/Hakko-FR-301-Portable-Desoldering-Too...