Here is some information that might work. I have not tried it since I still have the original FOB. Let's hope it works!!!
The Acura Legend, which is sold as the Honda Legend outside of the United States and Canada, was a luxury vehicle that was sold from 1986 to 1995. A luxury option that it came with the car was a remote keyless entry system that allowed the doors to be locked or unlocked at the click of a button. After obtaining a replacement, reprogramming new remotes--called FOBs--is a process that can be done at home in less than 10 minutes.
Contact an Acura dealer. Only an authorized dealer can order replacement FOBs from Kenwood. Kenwood manufactured the keyless system for the 1991 to 1995 Legends. The replacement FOB costs $30 (as of October 2010).
Insert the key into the ignition and turn it to "ON."
Press either the "Lock" or "Unlock" button on any remote. Turn the ignition to the "Lock" position. Turn the key back to "ON." Repeat this step two more times using the same remote each time.
Press either the "Lock" or "Unlock" buttons on the same remote and the door locks should cycle. This is to indicate that you are now in programming mode.
Press either the "Lock" or "Unlock" button on the same remote. The locks will cycle to indicate that this remote is now programmed.
Press the "Lock" or "Unlock" button on each other remote that you want programmed. All remotes must be programmed within ten seconds of one another. The door locks must cycle after each remote is programmed, or else the remote was not programmed and must be programmed a second time.
Turn the key to the "Lock" position to exit the programming mode.
Read more: How to Replace the Remote Keyless Entry Fob on a 1991-1995 Acura Legend | eHow.com How to Replace the Remote Keyless Entry Fob on a 1991-1995 Acura Legend | eHow.com