Know your lake's bathymetry. Take several depth readings, or enough to locate the deepest parts of your pond. Use a fish finder, depth sounder, or a simple delineated length of rope with a brick to sink it. Leave a float, rope and brick in the deepest holes for future reference.
Hire an electrician to bring a power source to the water's edge. If it is too expensive to pull copper to the shoreline, you can compensate for the distance between the water and the compressor with inexpensive terrestrial polyethylene air tubing.
Install a concrete pad for your weatherproof enclosure to sit on. Mount your air compressor inside the enclosure. Secure the cabinet to the pad to avoid theft.
Attach the air tubing to the outlet on your air compressor. Use clamps to secure the connections to the compressor. Bury the tubing in the ground from the compressor to the water's edge. If your winters are harsh enough to freeze the ground, trench the air tubing below the frost line.
Connect the free end of the tubing, at the water's edge, to your air diffuser. Clamp it down to ensure the tubing cannot slip off the fitting. Attach a length of rope to the air diffuser manifold and tie a small buoy or float to the free end of the float. Maneuver your boat to the marked deep section of the lake. Grab the rope and lower the air diffuser slowly to the bottom of the pond.
Run your aeration system for no more than 15 minutes the first day. Run it 30 minutes the next day and one hour the day after that. Everyday following double the run time until it's operating 24 hours a day.