Installation with Package Control
You can install GenExprForSublime directly using package control. If you don't have package control installed check this great tutorial. Once you have package control installed, simply type package install in the Command Palette, search for GenExpr and press enter to install. That's it.
go into your ~/Library/Application Support/Sublime Text 3/Packages/User folder and drop the GenExprForSublime folder in it.
If you have question or need assistance, visit e--j dev support.