Originally Posted by
vikatordacow This is what has worked for me to get updates:
1) Find a carrier who has released your particular phone model (the value of x in STL100-x matters) and the update in question
2) Pop in a SIM card from that carrier. Doesn't have to be an active SIM card
3) Power up device, you should see the carrier branding (and see carrier name in About -> SIM screen, etc.)
4) Check for software updates
Worked for a factory unlocked Z10 on T-Mobile; had to pop in a Rogers SIM to get 10.3.1. Also used this trick previously to get my Q10 updated to 10.2.1.
Note that this is my experience with unlocked phones using stock updates... don't know if this applies to locked phones or ones loaded with leaked builds.