How Do I Fit A New Helvar Ballast Lighting Unit?

[crmpicco]

I have bought a new Helvar L30A ballast unit to hopefully solve a lighting problem in my tank. The problem is I don't know how to fit it.

In the pictures below you can see the wires connected to the existing ballast unit, but I don't see how they come out.

Has anyone done this before? How do I get them out?

 

[Ch4rlie]

I think, there is a small hole above where the wire goes into, you push a thin screwdriver or blunt tool and push that in the little hole while pulling the wire out, might feel or hear a title 'click' and thats mean the wire should come out at same time.
 
Thats generally the case.