TO INSTALL:
untar, de-bz2 it...
(tar jxvf sonic.tar.bz2)
as root, cp the directory and its contents to where they need to be for X11 cursor themes
(cp -rv sonic /usr/X11/lib/X11/icons/)

TO MAKE IT YOUR X11 DEFAULT THEME:
Edit the Inherits= line in /usr/X11/lib/X11/icons/default/index.theme so that it says:
Inherits=sonic
(that\'s where the file is on slackware, anyway)

TO CHOOSE THIS THEME FOR KDE:
enter kcontrol go to Peripherials -> Mouse -> Cursor Theme tab -> then select sonic as your theme.