You’ll need 32 bit OS real or virtual. Special drivers and application to flash system partitions. Drivers are 32bit only!
I used 2 needles to connect to those pins and cp2102 UART adapter. Do not solder, you’ll damge the pins.
So the sequence is as follows:
Power the phone off (better use battery connector to power off)
Connect adapter’s RXD to the phone’s TXD (RXD <—> TXD)
Connect adapter’s TXD to the phone’s RXD (TXD <—> RXD)
Connect GND to any metal cover of the phone or to its metal border.
Now connect battery back and power the phone on with power button and you’ll see booting log in putty’s terminal. To stop booting press Ctrl+C right after vibro and now you’re in UART console.
Type "insdroid recovery" without quotes. The command turnes the phone into the recovery restoration mode. Remove your UART adapter now and connect the phone using usb wire. Install new driver. And flash recovery-uboot.img just throwing it with mouse on applications exe or use windows cmd.