For the on Plus 5T
Step 1: Download Driver and Unbricktool
Step 2: Extract Drivers and Recovery Tool files on Desktop.
Step 3: If you are using Windows other than Windows XP,turn off Driver Signature Enforcement.To do so,follow this guide :
How to Disable Driver Signature Verification on 64-Bit Windows 8 or 10 (So That You Can Install Unsigned Drivers)
Step 4: Press the power button for 40 seconds to turn off the phone.
Step 5: Press the volume up button for 10 seconds, while connecting the device with the computer.
Step 6: Open your device-manager and make sure in "Unknown devices" is one device with the name "QHUSB_BULK".
Step 7: Right Click on your device in the device manager and select Update Device Software. Choose manually the drivers folder and install the driver.
Step 8: When the device shows as "Qualcomm 9008", go run the MSM Download Tool as administrator.
Step 9: Click start at top left corner and wait for it to finish (green text will come).
Step 10: Disconnect phone from PC and boot into system.
thanks - @LloydSmallwood
Hier die Pakete ab Android 7.1
[OP5T][LATEST 9.0.8] Collection of unbrick tools
Quelle : XDA