This one has been answered several times by Bakepotato.
1... Deactivate any Mod's in the Freelancer Mod Manager if you have activated any.
2... Delete your Freelancer folder located at
C:\Program Files\Microsoft Games\Freelancer
* I'll say this again... Delete your Freelancer folder instead of uninstalling Freelancer to make sure there are no files that sometimes can get left behind after an uninstall, unless you check to make sure there are no files left in the Freelancer folders after you do a uninstall...
3... Delete or move any previous saved games... move the saved games to a new folder or delete all the files in your saved games folders.
Saved games are located in:
C:\Documents and Settings\your name\My Documents\My Games\Freelancer\Accts
Both, the Singleplayer and Multiplayer folders.
If you play online Multiplayer the saved characters are saved by the server you play on.
If you don't move or delete your saved games they can cause a conflict and will make Freelancer crash, this is guaranteed!
Why? Because there will be new ships, equipment and other goodies that will not be in your saved game files...
* When you activate a Mod you will need to start a new game.
4... Install Freelancer again with the Freelancer CD.
At this point I usually say to install the Freelancer QuickFix by Louva-Deus after you re-install Freelancer and before you activate the Mod but with the Crossfire Mod this step is not necessary because SWAT_OP-R8R already has it included in the Mod.....
5... Then activate the Mod using the Freelancer Mod Manager v1.3