Probably done by now but "Fisher WC Fixings" are the professional way to do this, they are hard rigid plastic "L" shaped brackets that are fixed the floor, WC is placed on floor and approx position of holes marked on floor , brackets are then located and fixed via Rawlplugs and screws inside WC template perimeter as per instructions with brackets, WC is then sited over top of brackets which are on the inside of WC so as to line up with holes on the WC, Bowl is then fixed to bracket through side holes.