[EFLC vehicle mod help]

Can someone please post what needs to be done to unlock EFLC so I can put some vehicle mods in it. I've been searching on google through all the sites and nothing is working. Please help.

[Need help, Game crashing after vehicle mod]

I changed a few vehicles, put the .wtd and .wft files in the vehicles.img and changed the handling.dat and vehicles.ide as required by the readmes. Now my game crashes during the game load screen, after the game has booted up and tries to load the save. I'm sure I didn't do a necessary step along the way, but not sure what it is. Please help.

I have Episodes from Liberty City from steam.