If using Lilidog, look in the installers under graphics to install these themes direcly to ~/.themes.

If using another distro, download and unzip the 'extra-themes-master' folder. Then, either make a folder in ~/.themes, and place the themes there, or put the themes directly into /usr/share/themes for systemwide use.

Either way, the themes will then appear in your system settings appearance dialog.

place the themes directly into /usr/share/themes for systemwide (root) use. The themes ending with "box" are the Openbox counterparts to the GTK themes.

Just remove the theme folders you one longer wish to use. the ~/.themes folder can be deleted as well.

All of my GTK, Openbox, and matching Geany and xfce4-terminal themes can be found here: https://github.com/sleekmason/Themes

All of the geany and xfce4-terminal themes are already present in the build. No need to download again.

feel free to also edit /usr/local/bin/ld-themes and add any new theme names you like to the list. Those themes will then appear in the auto themes dialog and exhibit the same functionality.