You can call in and request to have it unlocked. It does not matter that you bought it from someone else, the only thing that matters is that you've had it active on the network for 90 days, are the authorized user on the account and the account is...
You don't have to wait out the "FULL" term as typically at 4 months any remaining Device Balance will be waived if you are on a 3 year term or 3 months if you were on a 2 year.
There currently isn't an installment option. The best option usually is to try selling your phone privately and using that towards the Device Balance. You also have the option of instore trade in though I find private sale more reflective of the va...
If you really want the update then you can unlock your bootloader and load a custom operating system yourself. HTC didn't send an update for your model however they will allow you developer access to do it yourself. This will void any warranty you ...
