I have used this before with much success, it comes from Christian Samuel who posted it for me at the AB Forums:
Create a new logix file *.rss and set a master password like 99999, it has to be numeric entry. Save the file, close it and then open it. when you open it it should prompt you for the password. put in 99999 and then it should open. This is just to check the password capability. Then close the file and open it in Wordpad and search for 99999 it is usually located down about 90% of the page and to the right about 70%. This is where the password is stored. Now open your file with the unkown password in Wordpad and look in the same area as the test file. you should find your password.
you dont have the offline file then grab your oar and head UP that creek. lol
Christian Samuel
Sr. Controls Engineer
Good Luck,
Steve