Yes, it is possible to clear the programming by doing a Master Reset. Unfortunately, you need a service key (with SRV stamped on it) to do this. If you don't have one, or can't get one, you'll have to take the register to a dealer and have it done.
If you have a service key, here's the procedure:
1) Insert the service key and turn it to the SRV2 position which is at the 6 o'clock position or two clicks counterclockwise past the PGM position.
2) Depress the JOURNAL FEED key and hold it down.
3) While holding down the JOURNAL FEED key, turn the keyswitch to the SRV1 position which is one click clockwise or at approximately the 7 o'clock position. Continue holding down the JOURNAL FEED key until the register starts printing (may take 10 - 15 second, be patient) and then release it.
Hope this helps ...
Steve
December 2009