1. Install ChemCAD 5.2, but do NOT run it (you don't have the dongle, do you? ;).
2. Copy the crack file (eatcc52c.exe.exe) from 'crack' dir to ChemCAD directory,
   and run it (the dongle protection will be removed).
3. You can now safely run ChemCAD, enjoy the full version.

   Did I say have fun using it? :-)