dafeeeeeeeeeesh
The troopers have the layout of the ship, together with the cloaked ship they approach as close as they can to the air filtration systems, two of the troopers head to the ship and grab more of the same heavy backpacks, one of them opens his one up revealing a weird contraption of metal and rubber, that he places on the hull at the closest point of the air filtration system (or air tanks)
They then return to the ship, coupling with the weird device that appears to be a small airlock. The device activates, burning a hole through the metal plate of the ship quite quietly, using some kind of chemical. The interface is then properly compressed with air, and they board the ship.