How do you remove a 5804 fob from a 6128RF Keypad?

I want to remove old fob information from the 6128RF keypad to free up the space and add a new key fob. Can't find any information on how to do this. I assume I could put the 6128RF back to default settings and reprogam it but wa hoping I could just drop the one entry and it would let me replace it with a new one.