Chronicler had made a lot of progress in removing the smaller rocks underneath the massive rock. By a happy coincidence, one long rock happened to be stuck underneath the massive rock in such a way that it seemed to hold it up like a support beam. He decided to save that rock for last so that he would, hopefully, be more safe as he removed the last few rocks.
As Chronicler removed a few more rocks, he noticed the massive rock shift a little bit, forcing him to quickly get out from underneath. Fortunately, the rock stayed in place. "This is getting really dangerous now," he said to himself.
Eventually, Chronicler decided he had removed enough of the smaller rocks. He then climbed out from underneath the massive rock and stood to the side as he grabbed onto the last supporting rock. "Okay, everyone, I'm holding onto the last rock. As soon as I remove it, it's very likely that this big rock will fall on its own, so you'll need to at least guide it towards Redclaw as it falls. And don't worry, I'll be able to get out of the way quickly enough."
Chronicler then looked towards Redclaw, waiting for the right moment. "Get ready!", he said to the ones near the rock. Once he felt Redclaw was in the right location, he tugged on the last rock, but it didn't move. He tugged the rock again, but it still didn't move. This time, he pulled the rock for as long as he could until it finally came loose. Just as he had prepared for, the massive rock began to fall on its own, so he quickly moved aside, shouting, "Woah woah woah woah! Guide it! Guide it!"
Ruby saw where Redclaw was and, with help from her friends, pushed the rock in the right direction to hit Redclaw.
As the massive rock fell passed him, Chronicler laughed and said, "Redclaw, meet Mongo," the latter referring to the massive rock.
The massive rock, Mongo, hit its target and slammed into Redclaw's leg. It didn't hit with enough force to break a bone, but it was enough to bring him down for the fight.