In reply to jafferton91:
Sorry no GPX but the start of the route is grid ref SH 64857 58736
Any number of variations to get up to the arete. You could go along the path beside the east shore of Llyn Idwal then either;
Sub Cneifion Rib (likely to be very slippy) and traverse
Or
Take the climbers descent gully at the back of Idwal Slabs (likely to be wet)
Or
take the vague path that traverses up into Cwm Cneifion from about halfway along the Llyn Idwal