Unfortunately, I cannot provide specific installation instructions for the A500 Mini, as I do not own the device myself.
However, (real or emulated HW) if Workbench is already running on it, the process involves nothing more than copying or extracting the files into a folder and then launching the executable found there.
If it is possible to boot from a specific directory, that could also be a viable approach (assuming the zip file contains the necessary libraries and the startup-sequence).