Starting issue

Hi guys, having an intermittent issue with starting. Sometimes just getting a click when attempting to start, just like when a battery is completely flat. Put a new battery on it but no difference. Checked what wires I can see attached to starter motor and all look good.
Any ideas ?

Thanks

starter solenoid?

It's looking like the solenoid / starter. Are they straight forward to change ? looks a little cramped in the bay down there.