Huawei P8 help request

Hello everyone,

I purchased the Huawei P8 while in France and the carrier was Orange
I now live in the United States and my carrier is T-mobile
I would like to upgrade this device to Marshmallow but I'm not sure if I can or how.
Can someone please point me in the right direction? And I use a Mac..

EMUI 3.1
Model Number Huawei GRA-L09
Build Number GRA-L09C109B190
Android version 5.0.2
Custom version CUSTC109D250

The device is not rooted.

Thanks in advance.

P.S.

The more details you can provide when responding, the more it would be helpful... :)

from xda-developers http://ift.tt/1qnykWZ
via IFTTT