Desktop themes:
Download and unpack the archiv to ~/GNUstep/Library/WindowMaker/Themes. Choose the desktop theme from the WindowMaker menu "Appereance - Themes - Painting Desktop" or you may use the comand
"setstyle Painting_Desktop_1.tar.gz" to set the desktop theme.
PClock:
The archiv contains a background for the applet PClock. Run the PClock with the following comand:
"pclock --background=Pfad_to/Painting_Desktop_1.themed/pclock.xpm"
Icons:
Download and unpack the archiv "tar -xjf Painting_Desktop_WM_icons.tar.bz2". Have a look at the README. It contains the description for the icon settings.