Q. How do I modify a homework I have already installed?

A. Open up the source worksheet and open the MCtools section, execute it, and close it, (unless you have already done this in the current session), and make the modifications. Then re-save the worksheet, re-export it to html, execute the zipit line, upload it to mathclass, and re-install the homework. This is the editing cycle, which you will perform several times before the homework is just like you want it.