My battery needs replacing as now dead.

Quite embarrassing but I can't see how it is removed. It has a metal retaining clip on the front edge which doesn't seem to budge and a cable that goes along the right side of it that I think seems to also be some sort of retaining part.

Anyone know how the battery is removed?

Also does anyone know the type of battery to use as a replacement? (the current one is some make I've never heard of looks pretty cr*p).

thanks

Craig