1. Craft choral hydrate
2. Distribute diving suits around the Sub
3. Locate isolated target
4. Inject with Choral Hydrate to stun them
5. Remove radio, if possible overdose for a almost immediate death, if not place gas mask with welding fuel on them and inject with a poison
6. Disguise yourself
7. Open door and see if anyone is there
8. If cost is clear run away then remove disguise when no one is looking
9. If some one is there close door and put on suit then cut to flood the sub if on outter rim of the sub if not on outter rim of sub cut downwards and fall through hole, then seal behind you
10. Run until you think your are safe then remove disguise
Enjoy victory

You haven't mentioned it's a traitor guide.