Save Process as a Template

Hello, I am confused by the help topics on this issue, but I would like to save an existing (and still used and required) process app, so that I can create a new one from it. Reading the help text it would appear that if I 'convert' my process app to a template I render it useless going forward in its current state. Is this correct? If so is there a way to use an existing app as a start for a new one, without affecting original please?

Many thanks
Lisa