Submersible water pump re-wiring advice please

My wife and I bought our first caravan an Eriba Puck 230L, I think we ran the pump by mistake without enough water in the tank and consequently burnt the pump out. Got a new one (Reich) from the dealer in Poole but not sure how to fit it. The electrics are in an awkward place. Can I simply cut off the old pump at a more accessible level and join the new pump cable onto the old cable with a proprietry adapter? That way I wouldn't have to fiddle about trying to join the new cables into the system in a relatively innaccessible place. As you can see I am not tecnical and don't even know the correct names for things.

I hope you can help

John