If you have two controllers, you could just have your main account stay back while the guest does all the work. Thanks to CanadianWhizKid for confirming that this works. You could essentially do this on any level, but Tayari Plaza would be a good shout because its short. If you'd prefer to do it solo, or don't have a second controller then read on.
If you're having trouble with this, I think the best level to get this on is Uplift Reserve. When you start, run towards the flipped warthog, but don't get in it. Take out the choppers and wraiths with your laser. There should be operational warthogs to your right with gunners in them. Drive one with a gunner if possible. Then make your way through to the next area. You will come across another Wraith and Chopper, but they can be easily avoided. Make sure your driving skills are up to scratch. If you have lost a substantial amount of health at this point, you may want to restart the mission. You will also find a parked Ghost in the next area. Get in that and speed off. The rest of the mission is easy and can be sped past, apart from the area where you reach second platoon's location, just after speaking with the Colonel. There will be heavy resistance here. It will look exactly like that old firefight mission. As soon as you enter this area, drive off the balcony to the right, then drive past the first wraith, and try to manoeuvre around the second so that you will take minimal damage. This part is usually much more difficult on legendary, so it shouldn't cause too much of a problem on Heroic. In the room directly after this there will be a new ghost if you wish to swap for it. After this its pretty much smooth sailing from here. I advise you watch a video on the level first to get an understanding of it and you know which way to drive. You could get the par time at the same time, or get the Classic achievement if you're up for a challenge.