TP Link Archer MR200 V1 - extract bootloader for installation

Hi everyone,
I want to install OpenWRT on my TP-Link Archer MR200 V1. I have read the instructions on the OpenWrt website but I am a little bit confused about the step "now extract the bootloader from the stock firmware (the first 0x20000 bytes). (unfortunately, there is no guarantee that all future firmware versions include the bootloader. If you're in doubt, ask)".

Current Firmware: 0.9.1 1.2 v004a.0 Build 180502 Rel.53881n (Stock firmware)
Hardware Version: Archer MR200 v1 00000001

I really don't know how to start.

Grateful for any help or source.

Same for me , i am really confused about what i read on this website, install OpenWRT on this device looks tricky and not safe at all..