Go to the latest download in releases.
Press DIMOWA-yyyy-GUI-xxxx.zip to download the compressed files. Press DIMOWA-TABZ-GUI-xxxx.zip if you want it for TABZ and DIMOWA-OWA-GUI-xxxx.zip if you want it for Outer Wilds Alpha.
Find the file inside where your downloads go and move it to where you want, in this example I moved it to the directory where the game is stored.
Now decompress the .zip, I will use 7zip but any other program that can decompress this kind of file can be used.
Open the new folder and run IMOWAGUI.exe.
If it is a fresh download the program will look like this, with the Settings menu open.
Press the button Game Folder, it will open this window to select the game folder, in this example I choosed the TABZ modded v5 directory, but you can choose the GAMA_DATA folder too.
Now press the Mods Folder button, it will open the same window. Choose the folder that came with the program called mods.
Your screen should look like this.
Now press Save Settings, the following file and the two messages should appear.
Go to the IMOWA window, there you should see a single mod, the loader.
Check the check box and press the Save Modifications button, the new two green messages should appear too.
Close the program if you already have it open. After dowloading the .zip files of the mods move them to the mods folder.
Decompress them with a software and open the manager (IMOWAGUI.exe) again.
If you already have the loader installed and the manager has already run before your window should look like this.
Check the mark of the mods that you want to enable and press Save Modifications, if only the green message appears it means that it was succesfully enabled.
If you have more mods your window might look like this.
And if the loader isn’t installed you won’t be able to change the mods status and they will be grayed out, because they won’t load as the loader isn’t there.
Now after making the changes that you want, just run the game as normal.