I followed the directions. While nothing seems to have broken, the trackpad is now dead. It won’t power on. :( *sigh* Note, one thing I didn’t notice in the guide was the teeth that are on the bottom edge. a picture of that and explanation would be a good idea. The teeth that fit in the tabs can easily break off.

My tabs broke too. Like others said, these steps are misleading. You do not pull back as shown. I had to bend the old battery out which sucks.