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!