To find out how you can take part in the competition please send an email to the competition organizers at the following address:
amvj (at) alien-eye.com. (Your email address will not be used for anything other than with regard to participating in this competition).
More information about the competition can be found at the following project site: http://www.amvj-sessions.com/
The winning video will be used in the live stage visuals at a Boom Boom Satellites concert, or throughout a tour. The editor of the winning video will also receive a year's worth of "Donator" status on the org. (which includes Donators Forum access) If you have already donated, your donation period will be extended.
So start editing and send them some entries!

Note: They say that they can extend the deadline (which is soon), but only if they think it will increase the number of entries.