How To Roll Back To Miui 7

[RFontes]

Hi all,

I want to install miui 7 but I'm not sure about all the correct procedures.
I know that I have to wipe cache, dalvik and data, but do i have to wipe "system" too?

 

[wolfanger]

I think factory reset is enough.
https://twrp.me/faq/whattowipe.html