remove wheel, remove plastic wheel arch, take tension off belt and remove, lock flywheel, undo torx bolt on pully and it will easilly pull off, timing does not move as this pulley is on a keyway. replace and locktight bolt, put new belt on and check by rotating engine with spanner. 20-30mins.
see picture of flange after pulley removed and keyway.
the flywheel can be locked by inserting a chisel or simular into flywheel teeth nearest to top dead sensor. make sure it firmley locks while undoing pulley as it may slip and you might rap your knuckles. When tightening bolt, position chisel to lock in oppersite direction firmley.