I would open the file folder viewer and add the letters REM1, REM2 to the beginning of the file names you don't want used anymore. The software will go looking for its own standard naming routine and won't recognize the renamed file(s). This leaves you with the old versions in case you want to get some information from them through the PDF viewer. Once you are satisfied that you don't want them anymore (like next year just to be safe) you can delete the files in the folder viewer. Good Luck.
