Assuming you've put the "Tactical-Expansion" folder in your "mods" folder, all that's left to to is use this
to load the mod in the Sandbox. *****Back up your Crysis\Game\Levels folder first*****
Then open each campaign level and file->export to engine for each one.
As an alternative to the CryTools launcher, you could use a modified shortcut. Add "(space)-mod Tactical-Expansion" to the end of the target field, similar to this.
Hope this helps, feel free to ask if you're stuck.