Stereonet constructions don't get much easier than this. All you need to do is rotate a point by some angle around the center of the net. Strictly speaking, you don't need to do any stereonet operations at all. You can merely add or subtract the rotation angle from the trend of the point and plot the rotated point.
|1. Rotate the point shown by 50 degrees clockwise.
2. Calculate the trend of the rotated point (purple).
3. You can draw a radius through the new trend, then use a compass to transfer the plunge (open circle).
4. Alternatively, you can rotate the new trend to a vertical great circle, and count off the plunge to locate the rotated point (open circle).