well, that's new for me. I have always thought that three days was the curing out time. Three weeks is a long time to tell someone not to use the bathroom.
In direct response, do what every your instructions state.
caulk removal, if you removed all the grout then this cannot be that difficult for you. No tools for this, its your fingers and maybe a box knife. Your intention is to get a small piece that you can grap ahold of and gently pull off all the wall down the line, if it breaks start over again.
This is also not an easy job, but necessary for a good caulk job.