From St Andrews take the B939 Pitscottie road west. At the right-hand turning for Strathkinness, go left (south), and follow this road for a mile or so, negotiating a sharp right-left crossroads. The road then curves right (SW)and very soon you come to a junction, at the Drumcrro farm road. You can park in here at the gated track which leads north to Drumcarrow Craig - you can't miss it, there are two telecoms towers on top and these should help guide you towards it. It is visible from a good distance away because of these!
Sadly, there is little left of the broch itself other than a ruckle of stones and a cairn, made up of many of the stones which the broch would have been constructed of. The basic layout is still obvious, however - and take the time to appreciate the views. It was a bright November morning when I visited, and you could see for miles. Not much to see now of the broch itself, but worth the effort for the views alone. It's immediately obvious why this site was built on so long ago.