To fix the 'spinning barrel' syndrome, we offer this repair kit (also for the X3 and E46) that does not require recoding the lock or keys.
RegulatorFix BMW X5 E53 Door Lock Repair Kit - Front (left or right) : Amazon.com : Automotive
BMW x5 Door Lock | eBay
Also on our website:
RegulatorFix.com
or on ebay, store name: RegulatorFix
or contact directly:
[email protected]
BTW: still looking for a detailed DIY (write up, photos, video) or link.
If someone is willing to make one, I would 'donate' the lock repair kit!