Hiya',
From the top ..........
Goto SH4 install folder until you come to "C:\Program Files\Ubisoft\Silent Hunter 4 Wolves of the Pacific" assuming your on "C:"
You will see Files with these 3 Folders > Data-Registration Reminder-Support And a 4th "MODS" if jsgme is installed
Now the ROW etc whether 7zip/rar etc , You unzip/rar to that new DATA folder
Now ROW etc are in mods folder Un-zipped/rarred you can make a shortcut to jsgme to wherever and open jsgme up
Now mods inside jsgme will show on left side, To have them Working you add them using the top arrow button (enabled if you will) to the right side
Some mods may have a choice of folders to choose from for a jsgme install EG: Chronometer with 3 face color choices, So you would choose which color you want and then add just that color/folder (this is just to explain for future if you ever come across such like mods)
Hope this helps
Any probs come back and we'll sort you out
Ohh welcome to the forum
Have Fun
Def