That is where mine was on my 2007 330. No trick to the AC DC switch panel. I lay a towel over the bottom edge and let the panel hang by the wires when I’m working behind the panel. Of course secure all the power to it both AC and DC prior to opening it up. Do not over tighten the screws when going back. Ask me how I know. You are likely to find not only the sonar module (GSD 22 or 24) and an auto pilot course computer and the auto pilot pump if it is configured like mine was. I also had the Garmin 5212s. Recently replaced replaced with GPS map 1243XSV‘s. No sonar module required. With panel open also a good time to do some corrosion control work with things such as corrosion X WD-40 whatever you desire. You may like I did have the plastic cover for the AC side to catch on coming out simply reach in and push it out of the way. I also taped it for preventing future interference. That area gives access to the electronics box ram and a rigging tube that goes down to the starboard side behind the aft cabin starboard wall which gives access to another rigging tube going aft to the area by the generator. Wires can be run from there to the bilge , the area behind the engine gauges, and the electronics box.