Moosenoodles, if you've got the download version, you just install it with JSGME and you're good to go. No need to manually edit files. Those instructions are for folks who are looking to avoid conflicts with other mods.
As for your second question, there are two versions available on the first page, one with 9km visibility and added underwater vis, and one that is just LBO for slower machines. Take your pick, install with JSGME and enjoy those beautiful waves!