I need to replace all 3 gaskets in the boiler outlet. I have removed the outer filter cover and the first gasket but I cannot shift the next part in order to replace the final 2 gaskets. I have tried twisting in both directions...........pushing and twisting.......pulling............it doesn't budge. I'm beginning to think it's not meant to come out - even though the diagram of parts would indicate it needs to. Help!

Jessie, April 2018