Kitchenaid Dishwasher - how to get off the pump/screen cover

I need to inspect the pump/impeller assembly on my DW. I get the spray arm off, but there are several screws/fasteners holding the pump cover on. The pump cover has a large fine mesh screen.
Stupid question, but what tool do I use to get these screws out? They look almost like hex screws but they're not.
Thanks for the help.

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