They area real PITA to get out in one peice without either damaging the paintwork on the bonnet or breaking the little plastic sprung tangs off.
I found the best way was with a pair of long nosed pliers from underneath into the hole on the bonnets underside.If you can locate the 2 side tangs and squeeze them to the body of the jet it will start to clear the front of the bonnet.Once you have got it moving it should just pull out.Others would say a small screwdriver from the outside protected by a bit of cloth/plastic ets to stop damaging the paint work and then prize them out.When you replace/refit the pipework it is helpfull to warm it slightly as if it is more flexible it will go onto the nipple better..I used a lighter just to warm the pipe and it helped alot.
Sorry to say either way they are not an easy job to remove ...in one peice.Assuming they have the extra space filling of the heated wire connections, that should be unplugged and pulled through the underside to give you a little more space to get pliers in.
After having my bonnet repainted a while ago and finding all 4 plastic tangs had broken I bit the bullet and bought a new pair from VX..and yes that did hurt at £21.00 each