We can take a bike to the local locksmiths where they cut a key to suit the lock whilst the lock is still in place.
No numbers or old keys required.
Not familiar with the bmw setup, but many steering locks are easy to remove.
If its mounted in the side of the headstock and has a rotating plate to cover it. Many of these its a simple task of removing the pivot pin from the plate and thats all that holds the barrel in place.
Slide hammer with something like a self tapping screw attached to the end can work well, as the lock securing plates are generally soft and easily defeated.
Picking is another option of course.
Ok checked and the K75 should have a lock "cover plate" which is held in place with a pin.
Remove the pin ( if you can grip it pull and twist anti clockwise at same time) and with these types the lock will usually pop out with a small spring behind it.
