accessing another user's files


I bought a second hand ibook about a year ago, and have only just set up myself as a user, the problem is in all this time I have been using the first owners profile and I don't know the password, this means that I cannot get all the photos i saved in this time. Any ideas how i can access these files? If i delete my new profile will the computer start up in his profile without requesting a password (as it did before) or will i be stuck? many thanks.