NOTE = YOU MUST BE ROOTED.
Also, it is advisable to make a Nandroid Backup incase the device gets soft bricked, Although it is unlikely to happen.
1. DOWNLOAD and Install XPOSE INSTALLER, grant Xpose SuperUser right.
2. Lauch Xpose Installer.
3. Click on FRAMEWORK.
4. Click on INSTALL/UPDATE.
5. Reboot device.
6. DOWNLOAD and Install Imei Changer.
7. Open Xpose Installer.
8. Click on modules,make sure Imei Changer is ticked then click on Imei changer to Launch it.
9. Input the generated Imei and Click APPLY.
10. Reboot device. DONE!!