How can I roll back to the previous build. flyme 5.1.11.OG is terrible

I desperately want to roll back the software on my Meizu2 Note as it is impossible to install the GMS from the HotApps.
I installed the GMS Installer, but the GMS will not install.
I urgently need to use my GMail on my phone.
What is the last build no. ?
Thanks Adriane

Looks like your connection to Meizufans was lost, please wait while we try to reconnect.