If you acquire a copy of VisualDSolve (the Mathematica add-on which I demonstrated in class) you install it as follows. In Mathematica, evaluate the expression $UserBaseDirectory. You will get an answer which is the path to a directory, for example, on my Macintosh it is

/Users/fgoodman/Library/Mathematica.

Inside that directory there will be a subdirectory called "Applications". Copy the folder VisualDSolve and all its contents to the directory "Applications".

Note: the folder VisualDsolve should contain a file "VisualDSolve.m", a file "Wada.m", and three folders, "Documentation", "FrontEnd", and "Kernel". The folder containing this material is the one which should be copied to "Applications". Thus the correct route to VisualDSolve.m is:

$UserBaseDirectory/Applications/VisualDSolve/VisualDSolve.m.

After installing, choose the menu item "Rebuild Help Index" from the Mathematica Help menu.

The Documentation folder contains a whole book worth of stuff - many megabytes. To save space, you could remove all or most of it