Remove any dead branches. This bonsai has a nice shape, pinch or snip off the leaves on the tips to create "pads" I would want the interior of these pads to thicken in. See how the bottom branch curves down and out? Envision it being denser so pinch the tips on the top of this branch following the curve. Just stand back and look at it but don't be too hasty. I will leave branches or leaves until I have studied the plant and decide what I want to do. I think this plant has already decided for you. The top pad can be separated from the bottom by removing the small branches in between but again take your time. I might take you weeks to decide which one to remove.