Just cut both connectors off and use bullet connectors.
I was told not to solder as it could slightly change the resistance....how true this is I don't know.
Are they heated? if they are this is a bit more work as you need the carpets up to run the loom through.
If not its a very very easy swap.
Being a bit anal about such things, it would bug me having the 3-door tilts in a 5-door car so I'd have held out for a set of 5-door Recaro's though!! I bought a complete interior with door cards etc a few years back for a Golf I had (Grey on black) for £400 from our fave auction site. Really good seats and worth the change over. Had to change the plugs too - all of 10 mins work using soldered connections and heat shrink over the joint and no issues with airbag lights.