I instructed them how to find their overraked hands through pokertracker4.
Could you post a brief tutorial, or a link to a post with the info?
When looking at your PT4, set the statistics to sort by between dates 10/30/15-12/9/15. Then you'll need to go through each stake you played individually and sort the rake column by descending order. This should bring all the highest caps to the top. For any stakes under 4/8 you can start by looking for hands that charged above 2, all these are overraked. Additionally, any HU play that was capped above 0.5 at these stakes will be overrakes. Also, any 3-4 handed hands that were capped above 1. This is a little tedious, but you should be able to find the hands a little easier by doing this. Play around with some of the other filters and maybe you'll find an easier way to sort what you're looking for.