Huawei P8 GRA-UL00 got new firmware upgarde which is recently released by Huawei, according official changelog following are features of this update.

Features

• This update improves system security with Google security patches.
• [Optimizations] Improved device security with Google security patches.

• Download Link :GRA-UL00C636B364
• File Size : 1.57 GB
• Supported Model : GRA-UL00 (With C636 cust)
• Firmware type :  Official Full OTA

Installation Guide

• Make backup of important data
• phone should not be rooted
• Battery should be at least 50%
• Must be running stock recovery
• Make dload folder on SD card
• Extract downloaded firmware zip file and copy UPDATE.APP file in dload folder
•  Dial *#*#2846579#*#* and select software upgrade >SDcard Upgrade and update should start.
• 2nd way to update is switch off your phone then press and hold (volume up, volume down, and power) until you see update start screen