Windows
Plug-in installation:

C:\Program Files\Adobe\Adobe After Effects (Version)\Support Files\Plug-ins\Terrible Junk Show\
Place CuttanaNir.aex into this folder.

ScriptUI Panel installation:

C:\Program Files\Adobe\Adobe After Effects (Version)\Support Files\Scripts\ScriptUI Panels\
Place CuttanaNir.jsxbin into this folder.

macOS
Plug-in installation:

Applications/Adobe After Effects (Version)/Plug-ins/Terrible Junk Show/
Place CuttanaNir.plugin into this folder.

ScriptUI Panel installation:

Applications/Adobe After Effects (Version)/Scripts/ScriptUI Panels/
Place CuttanaNir.jsxbin into this folder.