Pathfinder

To Sgt. Heath
You'll spawn in a large field in the middle of the night. Go right, and you'll find a German wandering around. Your M1 Carbine is more accurate and easier to control, so use it. Once he's gone, you can either go left to find Heath or right into a building to find a small medikit. Either way, you'll be going left.

Once you get to Heath, you'll find that he was killed. Next to him is the equipment you'll need and a M1 Garand. The Garand will have less ammo when you pick it it up and it can't be reloaded until it's magazine is empty, but it does more damage than the M1 Carbine. It's your call. Grab the equipment either way.

Setting up the radio
You'll find a bunker just past Heath's corpse. Inside are two Germans playing chess. Since they haven't noticed you, you have a major advantage. Kill them with whatever weapon you want, then go inside.

Inside the bunker are a few medium medikits. Pick them up if you need them. When you're done, go just past the entrance, then go left.

You'll be in a large field. Walk up to the flashing radio silhouette and press your use key. You'll set up the radio, allowing your fellow troops to spawn in.

Getting to the end
Now that you have allies spawning in, you can move ahead. Quickly go past the field to the houses on the other side. The house on the far right will have a MG42 firing, but an explosion will get the house on fire and put him out of commission. When the house is on fire, run to it, and one of your allies will break open the door. Go left,, then right, and you'll be at the house's exit. A few troops will be upstairs, with the stairs blocked by furniture. The game will prompt you to throw a grenade, but you don't need to.

Now that you're outside, you'll be in what appears to be a chicken coop. This is a great area to use the Thompson and grenades at, since it's a pretty tight area. When this area is cleared out, you'll move onto house 2.

House 2 is just as tight as house one was, but this time you can go upstairs, even though there isn't anything there. When you're inside, take a left, then go straight. You'll be in a living room, where German troops will pull up in a truck and block the house's front door. Just use your Thompson and you should be fine. When they're gone, take a right and go outside. When you're outside, go through the nearby hole, and you'll reach the exit.