TP-LInk Archer C2600 - Reset to original factory firmware

I installed openwrt for fun/testing..
I am having lot of diffculties managing working with same.
I am not a core techy/networking person.

I want to reset to original firmware which came with this router.

Can someone please help how to do the same ?

Hostname	LEDE
Model	TP-Link Archer C2600
Firmware Version	LEDE Reboot 17.01.4 r3560-79f57e422d / LuCI lede-17.01 branch (git-17.290.79498-d3f0685)
Kernel Version	4.4.92
Local Time	Thu Oct 25 10:07:43 2018
Uptime	0h 56m 27s
Load Average	0.31, 0.19, 0.17

This is existing firmware, please help at earliest.
Even the wifi is not working on the firmware i am on.
I cannot even stop/reject access to few devices (phones/pcs).

Stock firmware was easy to manage that came alongwith router.