Installing and Uninstalling
If you have downloaded .scr file then copy it into your windows directory and run screen saver selection dialog, for that either go to Control Panel/Display and select Screen Saver Tab in the dialog window, or minimize all apps and right click mouse button on the desktop, select Properties item in the popup menu. In the screen saver dialog select your new screen saver and click apply button.
Uninstalling - If you have installed screensaver via installer package go to the directory you've choosen during the installation time, by default it goes to Programm Files\ScreenSaverNameHere and run uninst000.exe. Otherwise just go wo your windows directory and remove corresponding .scr file, e.g. - hikhukris.scr.