Shower doors seem nice at first, but after a while they get to be a pain to take care of. If it isn't an issue with hard water stains that fog and etch the glass, it's the mould that can grow in the track and other crevices. It's possible to remove the door so you can put up a simple shower rod and curtain that's easier to maintain.
Unscrew the screws that are holding the door hinges to the shower insert or wall.
Remove the screws and slide the door and hinges out of the opening. Dispose of the doors as you see fit, but consider taking them to a donation site if they're in good condition.
Scrape the caulk off along the sides of the door latch or magnetic strip that's located on the opposite side from where the door was attached. Also scrape the caulk off along the bottom track or water trap. Use a putty knife.
Unscrew the track or water trap as well as the door latch or magnetic strip catch. Pull them off of the shower.
Use a razor or caulk remover solution to scrape or remove the caulk that's still on the shower. If using a razor blade, don't scratch the shower.
Cut the tip off a silicone caulk squeeze tube with a knife, and fill the holes left from the hardware with caulk. Squeeze the tube starting at the back end of the tube to force it out the tip of the tube. This caulk is waterproof and will hold up to constant moisture. Spread the caulk flat with your finger to smooth it even with the shower insert surface. Use a tinted caulk so that it will blend and not be noticeable. Let it dry for several hours.