Don't do it. HID are not meant for regular halogen housing. The beam will produce lots of glare for the other drivers. Leave HIDs for HID housings. There are however two types of HIDs. Reflector based and Projector based. Projectors are like the type on the RS. Reflector versions are like the ones in the Envoy. Even those housings were designed for HID use.
Plus at least in Alaska they are illegal.