No real trick, I just loosen off the nut on the long thread so the J hook on the end pops out of the hole, undo the bolt that holds the hold down piece across the battery to the bracket on the inner guard and remove the entire hold down. Then undo terminals and take them off then you right to remove the battery. When I had to replace the battery that was in my car, the battery was a bit bigger than the one in it now and the top radiator hose was slightly in the way. I just took off the radiator cap and nudged the hose to give me enough clearance to get the battery out. Mines a 351 4V car, but can't imagine it being too much different to a 429 equipped car as it sounds just like my setup with the threaded rod close to the top radiator hose. If need be maybe loosen the top hose and remove that side only from the radiator and kink it back to give you the clearance you need to get at everything. Make sure the battery you get works before putting the battery clamp back on and fully tighten it. Should do the trick.