using NAT to rename lots of programs is about 1000 times faster and just a better way of doing it if you enjoy your sanity.
open the 'editor' folder in that left-hand column beside the main area. in that open the 'list'. then click 'add' and find your n2p files (make sure you did back them up somewhere first). then add all the ones you want to rename. now they should be in the list. go through and edit the 'program name' column, but leave the one one the left alone (the one with the actual n2p filenames).
when done hit save. doing it in nebula for lots of files would be an exercise in pure insanity compared to doing it this way.