Driver's side windshield wiper goes past window frame. How can this be repaired?

It could be a relatively easy fix or it could take some effort. First, try repositioning the wiper. By flipping up the end cap of the wiper arm and backing off the set screw that holds it on the wiper motor post. Remember, what position it was in by placing a piece of tape on the windshield. Pull the wiper arm off by pulling it off in line ith the angle of the wiper motor post. Take a close look at the splines of both the wiper blade arm and wiper motor. If either is damaged you will have to replace that component. Estimate the amount of adjustment you need and reinstall the wiper blade arm that amount in relationship to the piece of tape. Tighten set screw and try it.
If it still does it but less then repeat the process until you get it adjusted correctly. If there was no change thing it could be the wiper motor and that takes some effort to replace.