I did mine last weekend the classic way - taking all the drivers seat out, removing the parcel shelf and all that.
OK so I'm laying under the ignition switch for maybe an hour, I've broken two watchmakers 'philips' type screwdrivers and I'm pretty racked off. Final throw of the dice and I use one of the 'normal' watchmakers screwdrivers and it comes undone easily. :D I recon that it's all about the angle of the screw and a 'philips' driver just skids off whereas the 'normal' screwdriver just grips the edge of the cross. Might be worth a try for someone else.