How do I get the battery out of its compartment? I removed the leads but it is held down by two lips at the base. The compartment may detach to access them but the plastic side clips won't budge. I snapped two of the six off trying to lift them.
The battery is required to be held down firmly - it will fail the MoT if it is not. The lips at the base are often used - there will be a bolt somewhere which fastens a clamp over the lips. You will need to remove the bolt and then the battery will lift out.