How do I remove the water pump drive pulley on a 98 Cadillac Deville?

This is not the tensioner pulley or the pulley on the water pump this is the pulley attached to the engine drive. I can not get it off and I need to in order to replace the head gasket. Please help.How do I remove the water pump drive pulley on a 98 Cadillac Deville?It should have 4 bolts in the center holding it in place

scene hair

so thin skinned