Bootloop TP-Link RE450v2

I bricked my TP-Link RE450v2 and it is now in a boot loop. (All lights are flashing and never stop)
TFTP server method is not working.
Serial method (UART) is the only method how you might flash this repeater back to working.

First question: How do I figure out which one of the four holes is RX TX GND? wiki is not telling us.
Second question: Is it really necessary to unsolder R64 & R69 0201 resistors/jumpers as suggested here?
Any ideas?

.... according to the link you provided.

Lol, thank you. Still more important is, how to circumvent soldering?

you could try to point something sharp, like a needle towards one of the points that needs shortening.

but you need to keep in there until the manual work via the serial port is done.

Yeah that is not working, first you have to dismantle it completely, front side itself is not doing the trick. Back side is not easy to reach because of the socket. Time to let it go. Expensive upgrade fail. Thanks for your help @frollic.