I am installing a new fuel pump in a 1990 alfa spider. The manual indicates that after removing the 6 bolts you just slide out the entire fuel pump/sending unit assembly - but it won't fit through the hole as a unit. There is a clamp around the metal fuel tube that holds 2 pieces of a metal frame. I am worried if I loosen it something will fall into the tank. Is there something I'm missing here? What's the best way to proceed?