Hmm you can reflash stock but you will need the following:
Android Studio
Latest Google USB drivers witch you can get witnin Android Studio.
and a PC.
go to
https://developers.google.com/android/images select the firmware according to your device.
Get Android Studio Here:
https://developer.android.com/studio
Now on your pc open the 'Command Prompt' and type the follwing you will see the default directory is 'C:/Users/YourUserName'
Step 1:
cd AppData
Step 2:
cd Local
Step 3:
cd Android
Step 4:
cd Sdk
Step 5:
cd platform-tools
Now you have the command prompt setup go to downloads extract the zip and you might see another zip in that zip, extract that zip and place the files within that folder in this directory 'C://Users/YourUserName/AppData/Android/Sdk/platform-tools'
You also saw that in the 1st zip you extracted to saw 2 images this includes the bootloader image and vendor image rename the bootloader image to 'bootloader.img' and the vendor image to 'vendor.img' and move them to the same directory as shown above.
Now that you did this put your device in the bootloader mode and plug it into your pc.
Now onto flashing the images
Step 1 (flashing the bootloader):
Type this command in:
fastboot flash bootloader bootloader.img
Once this is done ensure you reboot your bootloader in your device for it to take affect.
Step 2 (Flashing boot image):
Type This in:
fastboot flash boot boot.img
You do not need to reboot the bootloader for this.
Step 3 (Flashing system image):
Type this in:
fastboot flash system system.img
You do not need to reboot bootloader for this step.
Step 4 (Flashing cache if available):
Type this in:
fastboot flash cache cache.img
You do not need to reboot bootloader, if this image is not available then skip this step to step 5.
Step 5: (Flashing the recovery):
Type this in:
fastboot flash recovery recovery.img
You do need to reboot the bootloader again before moving into the next step!
Step 6 (Flashing the vendor image):
Type this in:
fastboot flash vendor vendor.img
You do not need to reboot into bootloader.
Step 7 (Flashing userdata):
Type this in:
fastboot flash userdata userdata.img
WARNING: this will delete all data from your device.
You do not need to reboot into your bootloader again, but if this isnt available skip to the next step.
Step 8 (reboot your device):
Type this in:
fastboot reboot
Once it reboots it will erase your device and will boot normally if any issues please let me know!