How to service Huawei Huawei Y536A1 (Fusion 3) and Y550
  1. Get Huawei bootloader's code
  2. Unlock phone’s bootloader
  3. Flash custom recovery (CWM recovery)
  4. Root your phone with Sigma (Connect in Recovery Mode!)

You will get your smartphone rooted after you've performed all the above mentioned steps.

Once you have completed the rooting procedure, you can proceed to Direct Unlock operation.

Detailed step-by-step manual is located here