Smile [Q] Downgrade HTC Radar from windows 7.8 to 7.5

Hi all, I have HTC Radar C110e having windows 7.8 on it. I want to downgrade it to windows 7.5. I am a newbie here and i don't know anything about it so if anyone of you'll share a link for its guide i'll be really thankful. Details of my phone are:
OS version: 7.10.8862.144
Firmware revision number: 1750.0602.40603.401
Hardware revision number: 0002
Radio software version: 17.500.08.27_17.0850.06U
Radio hardwre version: 2.102.0.D4
Bootloader version: 4.6.175006.2(140733)