How to edit Frame Skeleton!

Hi! Does anyone know how to get into and edit a frame skeleton. I want to add another member to my existing frame but can find no way to properly access & edit the skeleton frame ipt. How is this done. Maybe you can't modify a frame skeleton after it is created. Appreciate any feedback on this!
Thanks!
Paul Rymal

Simply double click on the ipt node in the browser.
or
Right click and select Edit.
or
Right Click and select Open.
or
File>Open