Try this:- (Do test with 2 or 3 books first)....
1) Select the books whose author's name you want to split
2) Press "E" on kybd
3) Select Search and replace tab
4) Select authors in Search field:
5) Enter exactly .+ - (that is dot plus space dash space) in the Search for: field
Look down in the Test text/Test result area and confirm the split. On the left (Test text) should be the FULL author name as is now and on the right (Test result) should be just the title.... Don't do anything else YET. Confirm, confirm, confirm.
Now step six....
6) Select "title" in Destination field:
Recheck
Do it with 2 or 3 files first till you have it RIGHT.
When you are happy with the result of your SMALL test do the REAL conversion....
BE VERY CAREFULL as you can destroy your library with this procedure.
If you have the disc space backup your library onto another hard disc or external.... first.
You should be backing up before ANY complex process anyway....
BE CAREFULL