Not much mate. There is next to nothing to them. Just ring Ford and ask fr a Transit heater resistor and thell thenm the age of your van.

You will probably find the plug has corroded so you will have to cut the plug off and replace them with spade terminals. Make sure you get it right otherwise you;ll have the fan speeds all mixed up and the wiring for the slower speeds can't take the current for the higher speeds for a long time.