To install screensaver:
1) download this 'Merryn Lloyd - Screensaver Knockoff' folder to your 'downloads' folder on your mac
2) right click the 'Merryn Lloyd - Screensaver Knockoff.qtz' file and select 'copy'
3) go to your 'screen savers' file: to find it navigate to Macintosh HD/Users/your user (the one with the little house icon)/Library/Screen Savers
if you can't see your 'Library' folder right click in this finder window, select view options and make sure 'Show Library Folder' is checked
4) paste the 'Merryn Lloyd - Screensaver Knockoff.qtz' into the 'Screen Savers' folder (right click in this widow and select paste
5) now open System Preferences and select the 'Desktop & Screen Saver' option.
6) scroll down and select 'Merryn Lloyd...' screen saver
7) Keep the original 'Merryn Lloyd - Screensaver Knockoff' folder in your 'downloads' folder and do not delere the 'Merryn Lloyd - Screensaver Knockoff.mp4' video file, otherwise the screensaver will stop working.
Hope you're not too confused.
* UPDATE *
The above doesn't work :(