Changing family templates. I want to edit a family template, how do I do this?

in RVT 2013:
1) Create a new family from the desired family template
2) Edit as needed to get to your desired new family template
3) Save as a family (in the Templates folder or other appropriate location)
4) Change the extension from .rfa to .rft (accept the file extension change warnings)

Make a new family from the template, then save it as an rft, but don't overwriting the old template.

In Revit 2013 you can't change the extension and open it as a RFA. Will only work if templates are from 2011 or older.

Try this: Create new family > then edit it > Save as family > Rename the file from rfa to rft