On a mod's page you can find all information about a mod. Since you can't use the mod installation protocol, click on Download this mod to download the latest version of it. Your browser will download a .rmod file - that's the file format of all Raft mods.
The "Download this mod" button allows you to download a mod manually
2. Installing the mod
You can start the mod installer by opening the downloaded .rmod file. This should bring up the mod installer window as shown below:
Opening the mod file will bring up the mod installer.
You can now continue with step 4 of the main mod installation tutorial: