Close Gimp if it’s running. Download your favorite Gimp scripts from The Gimp Plug-in Registry. Right click the download link(s) and choose “Save as…”

Save the file to your scripts folder. If you’re not sure where your scripts folder is, you can find that by opening GIMP and going to File | Preferences | Folders > Scripts. If more than one folder is shown, any of those locations will work.

Once you have saved the file in your scripts folder, the new plug-in(s) will appear under the toolbar item called Script-Fu. If it’s not showing there, make sure the file is in your scripts folder and that the filename ends with “.scm”, not “.txt” or “.scm.txt”. Some versions of web browsers will append .txt to the end of downloaded files, esp IE. If you choose “Save as…” check to make sure the file type is set to “All files”, so that the extension of scm will be retained in the download.

Another way around this is to simply path out to your files in the Scripts folder and change the file extensions to .scm instead of .txt.