Take one step at a time.
 
1. Go into this folder :\Steam\steamapps\common\Batman Arkham City GOTY\BmGame\Config
and open "DefaultInput.ini" open in default notepad or best is notepad ++ (https://notepad-plus-plus.org/downloads/)

2. Press "CTRL + F" to open a search box type one of the "F" number keys (I use these as a hotkey feel free to choose your own) Save and close file.
Add the following bindings to look like this:

.Bindings=(Name="F1",Command="exec god.txt")
.Bindings=(Name="F2",Command="exec gear.txt")
.Bindings=(Name="F3",Command="exec enemies.txt")
.Bindings=(Name="F4",Command="exec gameplay.txt")
.Bindings=(Name="F5",Command="exec centre.txt")
.Bindings=(Name="F7",Command="exec ohk.txt")
.Bindings=(Name="F8",Command="exec cheats.txt")
.Bindings=(Name="F11",Command="exec graphics.txt")
There are other "F" numbers in DefaultInput.ini I use, so delete or rebind to different keys all other "F" numbers. 

Go to [Engine.Console] Change ConsoleKey=F10 to ConsoleKey=Tilde 

3. Go back into this folder :\Steam\steamapps\common\Batman Arkham City GOTY\BmGame\Config
and right click on the "DefaultInput.ini" file and click "properties" and tick the box "Read-Only"

4. Place any or all of my files in :\Steam\steamapps\common\Batman Arkham City GOTY\Binaries

5. When you press "F8" during game, my "cheats" file will activate. Test it by throwing a batarang or bolas. 
If it fails it means its activated and you need to RELOAD CHECK POINT for the mod to make the modifications to your gadget HUD.

6. When you press "F11" may see graphics change as a confirmation then RELOAD CHECK POINT from game menu to remove the BLOODY SNOW!!! (From in the city)

Optional Mod Files
(Feel free to customise)

god.txt F1
(Says it all)

gear.txt F2 
Max Grapple Gun & Batclaw Range.
Gadget Use When Hiding.
Infinite Ammo All Gadgets.
Thermal Scan Protection.
(RELOAD CHECK POINT)

enemies.txt F3
All Mines Disarmed
All Enemy Weapons Jammed
(RELOAD CHECK POINT)

gameplay.txt F4
Batman centre screen fix
Punch Break Explosive Gel Walls
Enhance Combat.
(RELOAD CHECK POINT)

centre.txt F5
(Centre character)
(RELOAD CHECK POINT)

ohk.txt F7
(Guess)

cheats.txt F8 
(All cheats on)
(RELOAD CHECK POINT)

graphics.txt 
(Snow and clean up scene)
(RELOAD CHECK POINT)

: Contact
• PM Me on Nexus Mods Site For Advise and/or Reports. I Don't Check Posts Everyday or Every week With Over a Dozen Mods I've Made.

:: List Of Games I Have Modded.
Batman: Arkham Knight
Batman: Arkham City
Batman: Arkham Asylum
Batman: Arkham Origins
Halo: The Master Chief Collection
Halo: Combat Evolved (Old Version)
Halo 2 (Old Version)
Kingdoms of Amalur: Reckoning (Not Re-Reckoning Remastered Version)
Livelock
Overload
Mechs & Mercs: Black Talons
Red Faction Guerrilla Re-Mars-tered
Red Faction: Armageddon
ReCore: Definitive Edition
Red Solstice 2: Survivors
Shadows: Awakening
Star Wars Jedi Knight II: Jedi Outcast
Star Wars: The Force Unleashed II
Star Wars Jedi Knight: Jedi Academy
Star Wars: Republic Commando
The Riftbreaker (If It Ever Stops Updating Long Enough To Update My Mod)
Vikings - Wolves of Midgard
Warhammer 40,000: Dawn of War II & Chaos Rising (5 Years In The Making & Then Some)
Warhammer 40,000: Space Marine
Warhammer 40,000: Dawn of War II: Retribution
Wolcen: Lords of Mayhem

::Official Disclaimer:
1.) I Own All My Games I Modded and Uploaded To All Sites.
2.) I Do NOT Own Pirated Games. I Have Added Screen Shot Of This Game (With Others Listed) From My Steam Account Library As Proof Of Ownership.
3.) Do Not Mention Pirated Games or Sites That Are Directly and/or Indirectly Connected to Pirated Games As This Information Is Monitored On Public Posts
and Forums By Site Devs. You Will Be BANNED!
4.) I Cannot and Will Not Guarantee My Mods Will Work With Pirated Versions, Nor Do I Support It.
5.) Banning HAS happened To Fellow Modders, Even Ones I know & Gamers Posting On Public Posts &/Or Forums As Well. We Need To Cover Our Rear Ends.
6.) Site Rules Are Strict & Will Always Be Respected & Followed.
7.) Credit Goes To The Company &/Or Developers Of The Games I Have Modded & Uploaded.