You will have to find a route to mount Kadar. The tank controls are very intuitive. You accelerate using the left analog stick and turn using the right stick. You zoom in by pressing the left trigger and shoot with the right trigger. To reload, use the RB button.
You can also boost with the A button, which is important in getting through the ramps. But during the mission, try to drive slowly, eliminating enemies from afar. Baird can fix the Centaur, so if you see fire coming out of the engine, stop for a couple second and wait for it to disappear.
Pass the frozen lake while driving slowly and carefully, because the slightest mistake can drown the tank. At the same time look out for Reavers. When you see one, stop and kill it and only then continue to drive. When you arrive at the bridge it will turn out to be destroyed. You will receive an order to find another way to pass the rift.
In order to do it, backtrack a bit and run over every single tree near the bridge. That way you will gain enough space to gain speed and jump over the rift using the ramp.
Don't stop before the icicles hanging from the ceiling. After the cutscene showing Locust preparing to defence stop and wait for Reavers to come from behind the hill. Get rid of them and the Locust accompanying them. Then destroy the troika near the gate.
In the end, concentrate on shooting the tower. By destroying it you will form yourself a passage towards the caves. Drive to Mount Kadar and look for the Locust's stronghold. The cave it pitch black, but the centaur has a searchlight. Drive forward, no one will attack you.
Until the Centaur breaks down, that is. During the breakdown three Corpsers will approach the tank. When only Braid fixes the engine and the spotlight, shoot them. But remember only to shoot once they've raised their limbs and exposed their vulnerable body parts. You should succeed if you will do it fast enough. The Corpser's speed depends on the difficulty level, but your tank will always be destroyed by a single hit and you'll have to start over from the beginning. The tank won't be able to move during the fight, so you only operate the gun.
After defeating the three Corpsers, three Brumaks will cross your way.