How do you fix power windows in a 1988 Mazda 626?

Since there's not enough info for a specific answer, here's the first thing to check.

You say Windows, meaning more than 1 not working - if none are working that would be the fuse for that whole window circuit. Check the fuse box in the driver area, and the fuse box in the engine compartment.

That's the first check - because you really don't just "fix" them without knowing what's wrong with them.