All depends on how theyve been fitted in the first place mate. With mine I wedged the angel eyes wiring into the sidelight bulb holder, that way I can just pull them out if i need to put the standard lights back in. Normally though the sidelight bulb holder would be chopped off to wire in the lights properly, so it would just be a case of getting some sidelight bulb holders and connecting them back up. As far as I know, the 3 pin plug for the main/dipped beam goes straight into both types of light.
Hope this helps mate