Yes, like railman44 said, you have to include a pic of the back with the rear cap removed. Some are hard to get off and you don't want to scar the watch if you don't have proper size tools. If you are not able to do this, hopefully you have a trusted jeweler that you can go to that will happily remove it for you at no cost. If they are a seasoned jeweler they may be able to help with some answers, otherwise, let you take pics and reattach.
The book idea is also a wonderful way to go if you don't feel comfortable removing the back and don't know a trusted jeweler.