In my review of the Kidd Single-Stage Trigger group (here) I mentioned that a known issue with some rifles is that the trigger fails to reset after the first shot. I made a short video that illustrates the problem and how to fix it. I want to emphasize there is nothing wrong with the trigger group, and the cutting done on the stock is trivial and doesn’t affect how it supports the action in any way. We did my friend’s stock the next day and he tested it with three mags full, in both precision and rapid-fire. It ran perfectly.
I prefer to use hand tools for this sort of thing, but I don’t have a set of woodcarving tools. A sharp, curved gouge would do this job without worrying about a power tool slipping. Others have used a drill successfully. As usual when tinkering with firearms, a light touch and a patient mindset are the keys to a good job.