these aren't model specific so tread carefully, but may be of use/interest:
http://www.ukgser.com/forums/showthread.php?t=125033
http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=542128
this last link (below) is 1200 specific and I think the 1150 boxes are easier to access and free the lock barrel. Also see underneath the link some comments pasted from the same link about accessing boxes
without the key. There willI'm sure be links specific to your model if you root around hard enough.
http://www.ebbo.org/re_keying.php
"Lock barrel removal without a key:
I get lots of emails from people who have purchased cases but don't have the keys wondering if they can still change the locks, here's what you can and cannot do.
If the case lid is OPEN and the lock barrel is in the LOCKED POSITION but you don't have the correct key.
You can still remove the lock barrel using the procedure shown above, just use a key that will fit the lock (even if it won't turn or unlock) or any hook tool that will pull the lock barrel from the case once its been released.
If the case lid is OPEN but the lock barrel is in the UNLOCKED position.
or
If the case lid is CLOSED and the lock barrel is in the LOCKED position.
You can't remove the lock barrel using the procedure shown above. You could try a lock smith to remove the lock barrel or you could drill the lock barrel out.
Buying a used case without a key:
If you are considering buying a used case without a key all I can suggest is you ask the seller to send the case to you locked, with the release handle pushed in and the lid open. Something placed between the lid and the case will help prevent damage to the lock mechanisms while in transit. "