First of all sorry for bad English
Step by Step Guide
1 ==> Enable USB Debugging and Unknown Sources from Settings
2 ==> Download KingoROOT app from
HERE
3 ==> Install app and ROOT your device
4 ==> Open BST Software and jump to MTK tab
5 ==> Connect your ROOTed device with Micro USB to PC and give RSA Key acces
6 ==> Select CPU Model MT6753 and IMEI Function ( DONT select COM PORT )
7 ==> Fill the IMEI fields
8 ==> Click start
9 ==> Allow all prompts on device's screen
10 ==> It should be auto reboot if its do not just reboot your device
11 ==> Check your IMEI from device
With my best regards....