For this approach you must start with a zip file containing all the classes in the package.
The basic idea behind the approach is to determine where the IDE looks for user defined packages. Once you have done this, unzip the class files from MyPackage.zip, copy them to the appropriate folder, and follow any additional instructions associated with the IDE.
Here is a list of environments in which we have installed packages following this general approach:
Remember in all environments there is going to be some way to install user defined packages, so don't give up.