l had all three of my belts snap and l was able to change the other two, but the AC belt can not be installed because the screw holding the pulley has a ''box'' around it.l can not get a regular wrench inside or a socket.Is there a special tool l need or do l need to remove something else as well?
Please no ''take to dealership'' .

Two Questions;

by the AC belt r u reffering to the drive belt the drives the AC compressor?

if so l dont think there is suppose to be a ''box'' there


Honestly what ur describing sounds very much like a maufacturer specific thing. The best thing unfortunately is to take it to a dealership

if not, try looking for a manufacturer specific shops, their r a lot of garages that only work on & specializes on imports, from Japanese to German. see if they can help

This is probably not a at home job

l cannot personal advise you on what tools or strategies you need for this. However, l would check 2 places that l have found to be VERY resourceful when owning a BMW. There are many helpful Techie type people in these sites / organizations who can help you resolve this question.

1. http://bimmerfest.com/

2. http://bmwcca.org/