Instructions did not mention the plastic film on top of the battery. Similar to a peel away film on a new phone. But it had screws holes in it and does not peel away as easily as a phone Peels away from edge easily enough but had a little "pull" to it over the cells. For now I left it. Quick google searches did not clarify the issue. If anyone can confirm I should pull it off I'll open it up again and remove. The install is easy.