getting the inner battery in & out is a pain, but after 3 months of use and about 6 re-wraps later i've managed to get the hang of things without scuffing up the battery sleeve... what works for me is to insert the inner battery from the left side, as upright as possible, simultaneously pushing it down against the negative spring contact and sliding it in. taking out the inner battery i simultaneously push it down against the negative spring contact and pull the ribbon to the left side, popping the battery off easily. same goes for the outer battery. the trick is to keep the battery as upright as possible.