Having had passed to me a broken PRS-T1, I decided to rip it apart. Below is what it looks like, for the curious. Note the battery (which has been disconnected in the pictures) is soldered to the board, so not very easily replacable/reusable.
Here is the PRS-T1 service manual with instructions on how to open the thing up. Basically it has (pretty tight) clips along the inside sides.
(Right click and save, or open in a new tab/window, if you want full resolution to zoom in on.)