need help to get top off of my Astral sand filter

I have an Astral sand filter. I bought a spider gasket from you and can’t get the top off the sand filter. I have gone on U tupe to see how to get the top off. They all show that you take the bults out and just pull it off. Mine does not have bults. I t had a little tab that I took off but I can’t get the top off. do I have to twist it off or what. Please let me know. My phone number is 505-321-4344.

Thank you Anne Fletcher