@kaveman You need to use installer 0.8.6 (there is an issue with .7) or earlier and it's best to have 15 sec adb from xda developers on your windows pc. Please remove all others first. The OPO needs dev mode on, usb debugging on, mtp trabsfer and an unlocked bootloader ( the installer may do this ifnot instructions are on the net) and you need to accept the fastboot/adb connection on your phone ( there will be a popup window on the phone). Then just follow the installer instructions. I would chose the wipe and bootstrap options when given.
You are best flashing from the original device OS so the partitions are not altered. Try a few cables as they can be a big issue and good luck. It's late forme so I will be back tomorrow. If you need help tonight try here https://t.me/WelcomePlus though it is latefor many and the weekend.
J
