I last led this walk for the Queensland Bushwalkers Club in October 2008. The walk to Egg Rock is now much less weedy than in times past thanks to the Gold Coast Hinterland great walk between Green Mountains and Springbrook.
Park as close to the start of the Lower Bell Bird circuit as possible. From here follow the Great Walk markers until you reach Nixon Ck. At this point continue along the 4WD track following Nixon Ck downstream until the road crosses the creek with Egg Rock on your RHS. Follow the side creek upstream at the north side of Egg Rock until you see a rocky cairn. At this point the track heads up towards a large rock slab.
You need to have someone in your group who is good with scrambling as the slab is a little trickier than it looks and most people will need or prefer a rope to help them up to the Leptospemum trees at the top of the slab. Don't do it if you would find Mt Beerwah any sort of challenge.
From the top of the slabs a track continues up to the base of the cliff. You follow the base of the cliff Eastwards until you reach a nice outcrop with a view to Palen Ck Prison Farm (where I would like to be locked up if I decide to commit a crime). From here the route is straight forward heading westward to the summit.