I've done the text editor bit with library files and it is tedious.  One thing to consider is, and I've had this happen after moving or deleting library files, if you open a Poser file later with those items in it you will be prompted for those items.

To save long waiting times for Poser to find or not find those items, I would go through any files that might be using those items and replace them first before deleting.

Poser 2, 3, 4, 5, 6, 7, 8, 9, 10, Pro 2014, 11, 11 Pro