Its a straight swap as long as you have the late 'central electric' version with the hazard switch on the top of the stalks. Don't worry about having to make the hole for the hazard switch bigger, as you can just swap the switches round and use the MK2 switch with the MK3 stalks.
Or you could fit the MK3 ignition cowling, then the dashboard, then the brakes, might as well fit the engine too while you're at it
