you need to cut off the clamps, then replace them. I thought you disconnected at the fuel pump and left these in place?
Reading again, and some google, and searching on here, I think whats not helping is my manual is for the later model and it has different fuel pump connectors, apparently.
Don't know these are the quick release ones, maybe there's a version with fixed pipes & jubilee clips ala 748E
The early ones used metal connectors that push into the bottom of the fuel pump. Unbolt the bar that holds them in place and pull out. Have a rag handy for a little fuel spillage.