Can't find the coolant drain plug???

Hi, Got a 2001 Jeep Wrangler Sport with the 4.0 six cylinder engine. It's
time to change the coolant but I want to know exactly what I'm getting into
first. Everything that I have read about this procedure says to remove the
coolant drain plug from the engine block. I have a factory service manual
that shows the location of this plug and says that it is on the left side of
the block under the exhaust manifold at the rear of the engine. It is very
difficult to see anything because of the intake, exhaust manifolds, and
exhaust pipes being in the way. I spent a great deal of effort above and
below the engine trying to locate this plug. I tried using mirrors and could
barely get my hand up in there to try to feel for it but I can't find it.
And even if I could, how do you get a wrench to it with out tearing half the
engine apart? It wouldn't be worth the trouble. Is it possible that they
didn't even install this drain plug in some of these engines? Is there
another way to drain the block? Removing the lower radiator hose doesn't
look like it would help because it's attached towards the top of the engine.
Could someone please straighten me out because I'm lost.
Thanks for any help,
Dennis B