How to reset a Master cable lock with red ring

I couldn't find this anywhere on the Master website, so thought I'd document it here.

We have a Master cable bike lock that has a red ring with two raised posts for resetting. While locking up his bike, my son managed to reset the lock so that the post would no longer insert into the combination part. I ended up swapping in my cable bike lock and taking his with me to work on.

I tried and tried to rotate the red ring so I could reset the lock and set it back to the combination we expected. It just kept springing back. The reason is that you can only 'reset' when the old combination is set.

Rather than try all 10,000 possible combinations, I figured out that I could deduce the combination by pressing the post of the lock into the combination tumblers and rotate them one by one to find the set combination. Each time a ring became hard to rotate, I figured it was set to the right number and worked on the next one. As I figured out the next number, the post eased into the combination tumblers until I had all 4 numbers.

Once the set combination was entered, rotating the red plastic ring was easy, and it stayed in place. All of the combination rings became completely loose, rather than resisting turning slightly. I set it to the combination we wanted, and rotated the red plastic ring back.

Now the lock works, and we know the combination and have it set to the one we want. I hope this helps someone out there.