Suggest you have a look at a later post like:-
http://www.subsim.com/radioroom/show...104514&page=28
Post # 594 shows pictures of the various options that are available and describes how to install them.
If this is still unclear, let me know which of the periscope positions you would like to have and I will try to explain in greater detail.
Cheapskate
PS If you are going to install with JSGME, this program will provide the necessary backups.