How do i install TL-MR6400 v5.3?

Hi there. New user here and i would like to safely install OpenWRT on my TL-MR6400 v5.300000002
however the firmware on the website says V5, not V5.300000002
so i am asking for a tutorial and if its safe to install

yes, vX.y = vX.

wait so v5.3, v5.300000002 v5 it doesnt matter its the same?

yes, in the world of TP-Link vX.whatever is vX.

oh okay. do i send it as a normal system update?

nope - https://openwrt.org/toh/tp-link/tl-mr6400_v5#oem_installation_using_the_tftp_method

i take Firmware OpenWrt Install URL and follow instructions?

yes, you do.

will this reset my router configuration?

absolutely

ok ive done it and now the power LED is flashing is this a good sign?

Hopefully it'll stop blinkning after a while.

it did and i now have access to the panel. how do i configure it to work with the sim card tho?

the sim card is not working...

it's actually described on the page you read earlier.

i dont find where

start from the top ... not from the install chapter.

nvm ill just reinstall stock fw. how do i do it?

I have no idea, one can only hope it's done the same way you installed openwrt.

now all LED's are going on, then only the power one then all turning off