In the VB Editor you can select individual modules (one at a time) and
Use the File > Export and File > Import to do this.
An easier way is to put the macros in a single workbook and same the
workbook to a disc.
Modules (macros) can be transfered from one project (workbook) to
another using drag and drop in the VB Editor window.
Just keep in mind that for the most part - the macros are an integral part
of 'a' workbook, any workbook.
If you haven't already learned about your Personal.xls you might want to
look into it. This is a great place to store 'universal' macros. Just know
that this workbook is stored in your XLStart folder and opens automatically
everytime Excel starts up. You can put other workbooks in this folder and
they too will open each time Excel starts up.