My van was running and just stalled out of nowhere. Fuel filter or pump?

What is your question?

I hear the fuel pump click when I turn the engine over. I figured I would just take the filter off and change it to see if that was it. Novice here... and I am broke as can be and honestly just want to sell the thing. I got the left clamp loose... the right clamp looks different than the left and no clamp to remove. Obviously don't want to put too much pressure and break the thing. How do i get that right side off?