MCU replacement

well stm mcus are pretty easy to kill 
the one in the pic is cycle8 pcb which for some reason has inverted pinout compared to standard ai0jst pinout..
since it has same jst port as other pcbs its normal to assume it will be same pinout but not this ig.
anyways user plugged in the jst which killed the mcu.. ldo and diode was supposed to stop this very thing but the all failed somehow.. 
also these 20k plus keyboards skimping out parts is pretty lame as well.. this pcb used a clone of original stm mcu named geehy apm32

anyways mcu is ded and we gotta replace it
hot air to take the thing out and solder new original mcu 
now these stm mcus require a bootloader for it to boot and load into program 
we flash bootloader via swd pins and then flash the firmware 
also replace the low quality ldo and diode with better stuff so if user make the same mistake again it stops at the ldo and diode and does not kill the mcu