Ok here we go
Firstly Download the mod to a temp folder
Then extract it to view the files
Double click the WSM3.0GWX3.0 folder
Then do the same to the MODS folder inside
Now you should see the mod itself
Double click the folder and inside you should now see a Data and MODS folder
Its best to remove the mods folder out into the temp folder and the go back to the WSM3.0 folder and place this in the JSGME mods folder.
Next open the mods folder you move into the temp folder and you will see 3 folders (Gel. Gell, Gelll) these contain the ships files you need only activate one of your choice.
So pick one and place it into the JSGME mods folder.
And yes this version is for use in GWX3,0 as stated in the title of the mod
( not sure if it works Ok with other Supermods)
Hope this helps