The fader isn’t user replaceable, so that replacement isn’t gonna do you much good unless you’re handy with a soldering iron.
You’ll want to use deoxit fader contact cleaner and a toothpick wrapped in a thin microfiber cloth to clean the fader rails. Do not apply pressure. A couple of cleanings should fix it.
Never, ever spray nothing to the fader. The residue will be cleaned when You do that, but it will flow from the fader out on to the PCB.s, and that can cause more damage than good.
When fader is broken - only replacement is recommended.
If You can get an ALPS faders with same parameters - same impedance and size + pinout - then go for replacement.
Best would be to fix it with someone who is experienced in soldering and general electronics disassembly.
As said, any fader that will fit physically and have the same electrical parameters will work. Best it to go for ALPS faders if You want long lifetime on them.