BMW Repair: Alarm Code, view id, indicator light

Question
Actually have 2 questions, 1989 325i 2 door hardtop. The car has not been used much lately, and the battery went dead. Purchased new battery and now when you turn the radio on to set the code it won't take. Have tried to leave the car in the 2 position for 1/2 hour and attempted the code again and it won't reset the alarm. Any help would be appreciated. I also changed the oil because the oil change light was on and it won't go off either, how do I reset that.  

Answer
Is it possible the code is wrong?  Get the number off the unit and see if BMW can put it into their system to confirm the code, other than that I don't know of any way to bypass the system.
As for the service indicator light, checkout:
http://www.bmwe30.net/cgi-bin/datacgi/database.cgi?file=articles&report=view&ID=...
or you can buy the tool for about $130 from Bavarian auto or ebay.
-cheers