For those hard to get spots like that, sometimes a round rod with the end rounded as well, use it as a punch with a dead blow hammer, and set the outside in a large shot bag. Or in a grassy yard. Or whatever works. Shortened wooden broom handle less likely to stretch
. Look at what you have at your disposal that would punch/pry/manipulate those outward from the back side. EVERYTHING is a tool. Find the one that works.