First thing I did was take out a drain plug on the block. It's a litle different on a Mach than the instructions due to our aluminum block.
Bad picture....but this is on the driver side rear of block.
The small plug is the one that comes out...have a drain pan ready and it takes a 8mm allen socket. After you drain out the coolant....replace the plug
with a little liquid teflon sealer to make sure it won't leak. Do not tighten this
much more than a little past snug. You do not want to strip this out.