Teardown

This is pretty straightforward, and when you load into the level seems harder than it is. As the description states, you need to make it to the end of this level without entering an additional vehicle to the one you start out in. Making a beeline down the left side of the map should make this easy.

I'd recommend having your shotgun out during this for any obstacles you hit a snag on.

Once you run out of space to drive the LTS boat, you're going to want to hop out and run to the left shoreline into the trees. If you're quick hopping and weaving through them, the helicopter shouldn't hit you much if at all.

Once you hit the train bridge, just swim under and hop back onto the left shoreline. Hang under the bridge for a moment if you need your health to regenerate.

There's an open section here that can attract some hits from the copter, but once you're back weaving in the trees you can use them as shields to help health regen again.

Once you get to the covered roadway you're almost home free, the copter shouldn't be able to hit you here.

At the end of the road structure duck out to the left of the building, you'll see a wall ahead that your rocket launcher or shotgun can make easy work of. If you're quick you can just hop up the left side instead.

Get through a couple more dense trees here and you'll be free to hop in the escape boat!