

1 - Download After Kerbin (Hopefully you've done that, since you're reading this!)

2 - Download and install Kopernicus - https://github.com/Kopernicus/Kopernicus/releases/download/release-1.7.3-2/Kopernicus-1.7.3-2.zip

3 - Download and install CTTP - https://github.com/Galileo88/Community-Terrain-Texture-Pack/releases/download/1.0.4/CTTP.v1.0.4.zip

4 - Download and install Scatterer - https://github.com/LGhassen/Scatterer/releases/download/0.052/Scatterer0.052.zip

5 - Download and install EVE - https://github.com/WazWaz/EnvironmentalVisualEnhancements/releases/download/EVE-1.4.2-2/EnvironmentalVisualEnhancements-1.4.2.2.zip

6 - Download and install Sigma Replacements - Skybox - https://github.com/Sigma88/Sigma-Replacements/releases/download/B_v0.4.0/Sigma-Replacements_SkyBox.v0.4.0.zip

To install After Kerbin, simply drag the After Kerbin folder to your GameData folder.
Any issues? Contact me on discord Gameslinx#0544, or the After Kerbin forum post.