Leonardo - custom VID/PID in sketch?

Hi.

I need to change the VID and PID of my Leonardo to something else (I'm trying to clone an existing device to use the existing drivers) but editing boards.txt is kind of a long way of doing it, is there a faster way? And, of course, changing the VID and PID means you can't program the board any more, unless you use an external programmer. There's no other way around this, is there?

Can I edit boards.txt to add a new board with the new VID and PID but old Leo settings to preserve programming capability, or something?