How to mod a mods?

[nebula-nova 3]

For the first I did try to find about how to mod sim city 2013 + cities of tomorrow, so I try here to find out more how to do it.

If am want to change a small police station to have a helipad with 99 helicopter ?

Where do I go to do that ?

I know to get SimCity-Scripts_287520926.package/SimCityDLCEP1-Scripts_287520926.package, and how to export to new package (I click on a file then a popup menu up and find export to package).

 

If you know the links for me to know so I can do this type of moding let me know, thanks.

 

My problems is that when I have more then what is max (car, tower, garage). it's disappearing from the game.  I can have more omega drones but I can't prevent disappearing from the game, yet.

 

Edit: I guess there is no one who care to help me out.

[Trylk255 23]

Oh yeah i will help you out.