One or two of the fields had invisible paths, which made for harder walking than we anticipated.
It's just a question of following the Jurassic Way out of Gretton, over a couple of fields and the old railway track, then heading to the edge of the woodland, along a grassy open 'ride'.
At the end of the lake, we turned left, still following the Jurassic Way past the house and turning left again behind the tennis court. Over the stile and turn right, and at the next waymarkers turn left across a field.
Keep heading more or less straight (southwest). with luck you find the crossing points, stiles or a bridge, with less luck you'll need to find them.
We arrived at a track and found a shady spot for a break. The track turns sharply right and shortly afterwards the path should lead to the left. These paths were not clear, but we busked our way across, eventually joining our original path to return to Gretton.