How to Revert TP-Link TL-MR3020 from OpenWrt back to Stock Firmware?

I have a TP-Link TL-MR3020 Version 1.7 Router that currently uses OpenWRT (Firmware VersionOpenWrt Attitude Adjustment 12.09-rc1 / LuCI 0.11 Branch (0.11+svn9425), Kernel Version3.3.8).

Considering that the uses of OpenWRT is not recommended and supported any longer for this device due to the limited hardware, I would like to revert back to the stock firmware:

It looks like the stock firmware from TP-Link for version 1 can be found here:

I have access to the router's OpenSRS UI via the browser (

I would appreciate some guidance how to revert back to the stock firmware.