What is wrong with the shower ceiling? Paint bubbling up, hole in ceiling, moisture causing damage?
Wha exactly is wrong with it? Can you describe the problem? Or provide more information? Post a photo? "Repair" is rather vague. Holes? Peeling? Mold?
I agree with the others, it would be helpful to know what kind of repairs you need. I picked one of them and found a tutorial for that specific problem. If this doesn't help, let us know. Wishing you the best.
There are drywall patch kits for small jobs at the home stores. We covered our unsightly ceiling with bead board. That was easy an looked GREAT!!