How do I beat Maximilian's tank?

I am currently in chapter 7 and having issues with Maximilian's tank, Batomys.

I can always get to the spot where he crashes through the base but I cannot defeat it at this point. I'd appreciate any help or strategy to try.

This is a summary of a guide found online as requested by Wipqozn. All information is from there, as well as images. Go to the guide itself if you want a detailed explanation and step-by-step instructions, this will be a less formal version.

Setup:

They recommend you start out by taking Largo, an engineer in one squad, and another Lancer. In the other squad put Alicia and Rosie (two Lancers) and another engineer. They note it's important to have those two in the bottom squad.

Steps to the battle:

TURN 1:

1. Take Rosie up the ramp behind her and take out the sniper, turn her to the right, and you'll find another sniper to take out. Proceed to the nearby ditch to crouch in before ending her turn.
2. Move Alicia up the ramp next. You'll see a few enemies ahead, try and take at least one out and then get Alicia into the base South East of you.
3. Now get each of the lancers from there and head him towards the tank, firing at the front turret with both of them, afterwards run to the same ditch that Alicia and Rosie were in. Also send the engineer into the ditch.
4. Next grab Welkin, get him towards your closest base, target the front of the tank and again fire. For your last action of turn 1, grab Largo and again fire at the tank's front turret. It takes 3 hits to take it out, and by this point should be gone if it was not already. Save the rest of your points and begin turn 2.

TURN 2:

1. Spend points on the two lancers in Alicia's group to take out the two left side turrets. If they aren't in place the previous turn, they'll have to waste points moving. (Make sure to end their turns fast so they don't waste shots.)
2. Have Rosie continue to take enemies near her out (crouched in that ditch until then). When they're gone, move her to the South East base.
3. Move Welkin through the second base, and up the hill. Blow apart the blue rock to clear it. Spend your last points on Largo's lancers to try and take out a turret on the right side. (There should be two guns left).

TURN 3:

1. Use Largo and his lancer to finish off the tank's guns. You'll likely need engineers to come resupply them with ammo at this point.
2. Generally you will start moving all your units to the South side of the map. Have a lancer knock down some of the blue wall.

TURN 4:

1. Get Largo onto the back of the tank and take two shots at the radiator. Get off afterwards and head South. You need to get shots into them and then take them out as they reappear.
2. Have the other lancer(s) closest do the same thing. (Shot, get off, go South). Send an engineer to resupply them afterwards.
3. Move Welkin farther up the hill and knock out the last blue wall. Set him up atop the hill, a bit left.

TURN 5:

1. Enemies will spawn North East, right for Welkin to finish off. Send the lancers and engineer to the West side of the tank.
2. Rosie and others should be by the South East command base. This turn is about moving into position.

TURN 6/7/8:

1. Have a lancer put three shots into a radiator that is not hurt, not taking it out. Move all of the other lancers into the Southern trench. Don't destroy radiators and wait for the tank to get into position.
2. (Turn 7) move the guy who shot the radiator into the south with everyone else.
3. (Turn 8) move anyone not in position, otherwise save command points.

TURN 9:

1. Tank should have shot, so move in a lancer to finish off the rear radiator. This will cause a girl and troops to spawn - send the lancer back to your troops.
2. Welkin is setup to destroy the enemies (girl and crew) that just spawned. Otherwise we're waiting for the tank to fire again.

TURN 10:

1. Welkin should have finished off the troops that showed. Otherwise move him towards the South East base as well. Anyone not in the ditch/crouching should be. Turn 11 was a wait/save up period too.

TURN 12:

1. After it fires, run up and take out the last radiator/generator. It is now vulnerable. At this point, you are just firing rockets repeatedly until it dies, and it eventually will. Use engineers to resupply as need be.