E34 1994 525 TD CENTRAL LOCKING REMOTE PROGRAMMING

I've just bought a spare single button remote off ebay for my 1994 525 td . I thought that you could reprogram the remote by taking the chip out and placing it in the alarm box under the back seat. But unfortunately the chip is soldered into the circuit board in the remote so it can't come out. Can anyone tell me if these remotes can be reprogrammed and how to go about it. Thanks Jed