You will use an axe to chop boards away on this back shelving unit and it will reveal three arms here. You can attach each of them to the robotic moose, and each of them has a different tool attached to the end of it. This achievement requires us to use all three arms, so you need to use the incorrect arms first, and the correct arm last. When you use the correct arm, it progresses the story and you won't be able to use them anymore, so you must use this last.
The middle arm with the circular saw blade is the correct arm, so you want to use this one last
. So, first, use the left arm with the feather on the end of it. Attach it to the moose and click on him so he goes out and attempts to use it. He will fail, so click him again to bring him back in. Next, use the third arm on the right which has scissors on it. Attach it and send the moose out, he will fail again, and click him to bring him in. Finally, use the second arm with the circular saw blade. This time, he will be successful.
Achievement unlocked! :)