Some of the camera lenses are off center - it is housed in a rubber housing attached to the board with a type of double stick foam rubber tape - you can take a small needle - pic - or a jewelers type screwdriver and slightly push the camera back into position.
The circuit board is attached to 2 notches at the top of the pen where the on - off button is - the other end of the board is secured by the plastic around the usb part that is removable [ not recommended ] . The ly-po battery rest on top of the board with a thin type of double stick tape - the mic is resting just below the camera lens behind the clip area - removing the whole board is done by only pushing it down from the top and not twisting - twisting at first will break the 2 notches that hold it in place at the top of the pen - with the bottom of the pen detached to the usb part - push the board down from the top - you will have to heat the area a little around the plastic Ferrell around the usb part first to break the glue - push down with a little force and the Ferrell will start to come out of the pen - this is the only safe way to remove the board and you will might ruin it anyway. The top of the pen should be removed first - it comes off easy - take a razor blade and guide it carefully along the seem to break it a little - then - by using a pocket knife as I did with a fine blade - popped off the top - then you can help to push the board out of the socket - still difficult - to get out but not impossible - by removing the top you can adjust the lens a little easier to line up with those that are miss aligned a little. The mic and camera are placed on the same foam rubber double stick tape - the battery is just below the mic laying flat on the board - the battery is labeled " PL561233 " You MUST ALSO remove the clip on the front of the pen housing that clips to the pocket before trying to push out the board from the top - this is easily done by slightly prying on both sides a little - then by popping it off using a pocket knife from the top of the clip holder - otherwise the rubber housing and mic will get caught up in the clip holder. So - remove the top - remove the clip - push down and their is a little glue holding the plastic Ferrell around the usb part - heat it up a little to break the glue - easier to pop out the board - don't try to remove the plastic Ferrell around the usb part - not necessary when replacing the battery [ if you can find one ] but can now be hard wired to a battery pack with a little thought and electronic knowledge. Hope this helped a little.
Kevin