Ok Im at my gaming PC now but I did these mods a long time ago so I cannot remember exactly which entries I fiddled with. I can however tell you all which entries to look at.
Of course I gotta say the usual -
make sure you back up all originals. You will also need a utility to look inside .pak files (Alzip does the job nicely). Basically you will be:
1. Looking inside the .pak folder
2. Selecting the relevant folder
3. *Dragging* the relevant .LUA file to another folder
4. Disabling "read only" on this .LUA file you dragged out
5. Editing it in notepad
6. Re-inserting the file into the .PAK folder
7. Save the .PAK folder
You wont have to do this all the time. For some tweaks you just need to dive into the .PAK and delete the entry.
The files that need to be tweaked are located in Far Cry\FCData
Objects.pak
Scripts.pak
Now this is where memory fades since I did this a while ago and cannot remember *exactly* what I edited but Im sure you lot will soon figure it out.
Lets look inside scripts.pak
Scripts.pak>Scripts>Default>Entities>AI
Here it is opened in Alzip:
*This* is where a lot of tweaking went on and this is where I totally disabled the silly AI choppers by fiddling with:
gunship.lua
Helicommon.lua
Again I cannot remember what the exact tweaks were but if I have time I will have a look. They are large text files and finding out what tweaks were made is a mission
But anyways...should give you all and idea of what to look for. You could also try the mods out there that remove the helos although none worked for me which is why I did them myself.
As you will see when you look inside these .PAK files its a
wonderfully tweakable game. You can give your handgun the power of a cannon (haw haw haw!) and give the telescopic-sights on weapons even more zoom! For example here is a tweak of the sniper-rifle scope to give it 40X Mega Zoom hee hee hee:
ZoomActive = 0, -- initially always 0
MaxZoomSteps = 8,
ZoomSteps = { 3, 6, 12, 18, 24, 30, 34, 40},
I think the default ended at 12 and I went to town after that
Another tweak - do you want a Super-Jump like the Incredible Hulk? Pick a weapon you dont like to use or hardly use. I chose the machete. Now open machete.lua and change the "PlayerSlowDown = " entry to:
PlayerSlowDown = 15
Save the file and go play the game. Find an elevated part of the land - like climb a small hill or something. Pick the machete, start running and press the jump key - HAAHAHAHAHAHAHAAHAA what fun
Not so weird looking if you can tell what it was without listening to the storyline 
