the same as vanilla assault on the control room honestly you've basically gotta throw a grenade before the first checkpoint and be trying to shut down everything that comes through that doorway
it sucks that you have to watch the cutscene again if you get it wrong but it's not that different to the original game in that respect

Once you get through that part there also seems to be a "feature" where a quarter of the way through the mission there are no more checkpoints, so if you make good progress after Johnson picks you up in his warthog, but die any time after that, you have to restart from way back before you even see Johnson.