Programming key to select specific seat memory

I have a 1999 328i with premium package, 2 remote keyless entry keys, and power seats with 3 memory settings.

According to the manual and the dealer, I can setup each key to automatically select one of the three seat memory settings upon unlock (e.g. Key A selects Seat Memory 1 upon unlock and Key B selects Seat Memory 2 upon unlock). The dealer wants to charge me $70 to set this up though.

Is there any way to program this myself? Does anybody know of instructions on how to do this? I can't see why they would sell me all of the pieces to the solution and then charge me $70 to actually set it up.

Thanks in advance.