Timing chain cover

My husband has a '93 Olds Achieva, 3.3L engine, automatic. He is trying to make his own repairs using the Hayes manual. He is also using the Chilton manuals but is totally stumped on this particular matter:

How do you remove the cover that is front of the timing chain (crankshaft balancer)? According to the manuals, he should be able to manipulate the cover by hand. He's tried that and he's tried using a breaker bar without success.

He can not find any pictures or more detailed explanations in any of the repair manuals. If you know, please help!

Thank you.