Place down your ALiVE modules like your normally do.
I will first decide if I'm gonna have an FOB, start on Nimitz, or start in a "black site" off map.
You'll always place the CORE module down first. That's the main module.
If I start on the map at an FOB or on the Nimitz I will place the SOCOM desk module down where I want it, the Diver Module down, and the HALO/Para Module down. There is an option in the HALO module to place your aircraft on the NIMITZ FYI.
If I decide to start "off map" at a black site...I choose that option in the CORE module for Spook. Then I place down all of the other modules I want as well in the corner of the map (location won't matter if you are off map).
Once the modules are down I start the game....then I go to the SOCOM computer and generate a mission. Once generated, we decide how we are going to insert....by air or by sea. Either way..you then proceed to the Sub station or Halo/Para station, gear up, pass inspection, and board your vessel.
Then you're off....rest of the mission works the same as any other ALiVE mission in regards to extracting by Helo Combat Transport support, etc.
You can also ignore using the SOCOM desk and create your own specific tasks as you would on any other ALiVE mission. The difference being, you place down the HALO and SUB modules and use those as one of your insertion techniques.
I like to set up at an FOB onsite, call for a Submarine....then have our unit fly by ALiVE Helo to the Sub, drop in the water, board the sub and then infiltrate via Sub.
When playing MP, it all works the same...just make sure you allow your teammates to spawn in on the plane, sub together before jumping/disembarking.