I am posting this in case any one else wants to know:
There is a fuse behind the radio. remove radio with a tool which is almost shaped like letter U, available from car dealer or make with old wire hangers Insert one into two holes at left and one into two holes at right.Remove radio. Remove two 'plugs' and ariel at back.Thefuse is in the back of the radio, so put it standing on front and remove fuse. Insert new fuse and connect up ariel etc then slide radio back in till it clicks into place. Sorry cannot do illustrations.
Thanks guys for help here