HELP Unable to add or take off books

[arl215]

Hi, been following this forum and looking for help. I have a PRS 505,I'v had it for almost two years and love it. The last few days I am unable to remove or add any new books. I have tried to re-format the device following the instructions hoping to remove all of the books and start over. I have about 260 books on the device. I do not have a portable SD flash. Any suggestions is greatly appreciated. I would hate to have to mail it back to Sony or the battery. The re formatting never worked I tried it twice. The battery seems to need plugging in every other day. Has any one tried to replace the battery themselves? I found a video online. Thanks in advance. Getting desperate.