How can I mend my shower?

My shower has water gushing out of the grille at the front of the shower. I have been told that this work does not involve a plumber. How do I go about mending it?
Anne-Marie Egboh, August 2003


done
it is an electric shower, a creda 8500dl

julie, April 2012
my shower stays hot for one minute then goes cold.but makes a noise when turned off like there wind in the shower and a gush of water comes out

julie, April 2012
if it's an electrical instantaneous shower replace it they are not
that dear

chris, November 2004
You dont say which type of shower it is. clues please.

derek, June 2004