Urgent!! Help needed trying to change rear pads

[Tank.]

I have an A6 4F, trying to release the parking brake to change rear discs and pads.

Following the directions from rosstech wiki but nothing seems to be happening.

I dont have the car connected to a battery charger, is this the issue?

Ive gone into the control module 53,
Basic settings
group 007,
Nothing happens,
Theres a drop down box where you can select open rear brakes so tried that, but still nothing happening

Do i need to enable security access first? this i also have no clue what my code is, any help much appreciated

 

[Tank.]

cancel last,

was my own stupidity,
I was typing group 007 and pressing the enter key, where i should have pressed the GO button on the user interface,

Lesson learned for next time

 

[leegsi]

Thanks for the update