i did the reverse on a set of mondeo lights that went for normal to xenon, and trust me, it's a bit of a mare

first up you've got to get a patch loom made up to go between the xenons and the normal lights, which means you have to gut the xenons to get the plugs off the ends, but more on this later

do your plugs look anything like the ones listed here ? in which case you can source them from a mondeo, much easier