Small Engine Troubleshooting Problems? Ask a Mechanic Now.
You will have to clear out all of the remotes and then program back in the remotes that you want to keep working. Here is how it's done on most liftmasters:
Here is how you program the remotes back in:
I'm sorry, that wasn't clear.
You have to erase all openers (also called remotes) and then program in any openers (also called remotes) that you want to continue to use.
How old is the unit? Some of the older units use rocker switches to adjust the fixed access code rather than a constantly rotating code like the newer (less than 10 year old) opener units.