i know that sometimes that might be a pain in the butt to remove... but whatever you do, dont pull on the wires!
i assume that your connecters are just like mine... tight and hard as hell to disconnect
there is a tab on the top that you need to push down (you prolly already know this though)... just push that tab down with your fingure ot a flathead screwdriver and wiggle the connector free... it might take up to a whole minute of wiggling, but it will come free.
when you have finished installing your gauges, before reconnecting the wires, put some oil or vaseline/petrolium jelly around the plastic parts - so that if there is a next time when you need to remove them - it will be a lot easier.
for me, the blue one was easy to take out.. the white one has always been a bitch - i've gone through this on 2 sets of gauges and a blown gauge set... so i know what the deal is