I approached this hill from the minor road above Trefor at SH368462 (where parking was difficult) on the path SW from there. There is a good path to the summit (not shown on LR123) from the quarry road at about SH362454. I think you can park on the quarry road from Llithfaen to the south.
(1 hour 40 mins, 2 miles, 1500’ of ascent)