You just just finished storming the Normandy beaches, destroying the Atlantic Wall, and saving your unit from certain destruction. You think you'd get some kind of rest but noooo, now you got to take out three 88mm cannons hidden somewhere in the forest. This is probably the hardest mission in the whole game. You will be faced with challenges from the start. First start walking out into the clearing, run back when you hear artillery shells. Wait untill the barage is over then run to the stone wall. In the area to the left the krauts put all kinds of crap: MGs, snipers, and regular troops. Your sniper rifle and BAR come in handy when taking these krauts out.
Once you take these guys out you go into the forest by the path that's in front of you. When you walk down the pathe you cross a stream, then you see a house, there's a kraut behind it and two behind the trees at the right. There's an opening into a big open area to your right, there are troops and officers in it. You do not have to go there and not doing so will save you ammo. This area does however have a lot of MP-40 ammo so if you use this gun to kill the krauts instead of the BAR you can actually get ahead in the long run.
Continue to walk down the path, there will be a kraut where another stream crosses. When you cross this one be careful, there's a machine-gunner at the end of the road. At the left you will find the first gun, there are like 4 soldiers and an officer around the gun. kill them and blow it up with a satchel or grenade. Go down the slope of the hill. There are two ways to go: there's a gap between the hedgerow and the house at the right and an open area left. For now you must go left. You will find a slope and another cannon at the top (there are 4 soldiers and an officer around it). Once you take care of the gun go to where the gap in the hedgerow is. There are 4 soldiers and an officer in and around the trucks.
Getting the third gun is the hard part. First go up the road that is in front of you. You will see a shallow ditch going along the side of the road. Go along the ditch as far as you can but so the tanks don't see you. There is a barn in front of you, there is a tank on each side. Opposite this there is a field behind a small fence. There are two snipers by the part where a path breaks into the forest. Kill them then go back along the path. Now walk on the left side of the road when you get to the beginning of the fence quickly jump across it and duck. (This requires as much luck as skill) Walk while ducked to the break in the forest. There are about 3 krauts on the path to gun #3 and 3 more plus and officer at the gun. Once you take the gun out go back through the field (while ducked). Go to the far right, jump the fence, and run to the right. Now crawl (walk while ducked) through the ditch (try to go exactly down the middle or the tanks might spot you). Go until you get to the end of the ditch, jump out and run for the big wood gate. When you reach the gate it will dissapear and you can get to the "radio box" and end the level.