Is there a quick fix for the light on the dash which will not come on when the parking brake is engaged?

I've changed a few in that generation explorer. The instrument cluster has to come out which isn't difficult, but takes a while as all sorts of things have to come out to get to the cluster. Do not remove the lens on the front of the cluster as you may knock off the indicator for speed and you will probably have to get it recalibrated. Once everything is removed there are only a few screws around the cluster to remove it. Be careful as there is not a lot of slack in the wiring harness. You will have to reach behind to disconnect the electrical connections. Change all the pulps while in there and test prior to reassembly.

Something like a Hayne manual should give you the procedure for removing the cluster. Use plastic cups for different types of screws/sizes and label the cup. You are going to have a bunch of them.