Same way Osama's Talibuddies got their APC's that we were popping in the mountain passes up there -- put it in low gear and drive.
What was your objection, anyway?
I read a lot of reports on Tora Bora, never read any mention of APCs within 30 miles of the fighting.
The Crusader was 70 tons. It would have taken two weeks to get it within 40 miles of the fighting. It simply could not have brought anything to the fight, especially as the enemy would have left while we were building the roads to get it there. At any significant range, it could not have hit anything on a far slope.
Heavy mortars were what we needed.