You have the skills and knowledge to do it. If you wish to avoid the need to hire a professional, understanding the basics of solar maintenance procedures can allow you to accomplish what has to be done.
Shut off the power prior to start. This can help prevent injuries while operating the machine.
Switch off the circulation pump. This is done by shutting off the power supply to the pump.
Shut off the supply of cold water. It is then safe to take out the thermostat and electrical element of the water pump. Once these have been removed take the water out of the tank. Then cleanse the tank. You should also ensure that both the electric element as well as the thermostat working properly. If not, it is best to change them.
Take off the panels. Verify the fitters for their proper align. Fittings will be found at both the corners and at the bottom.
For more details on solar power and maintenance Please take a look at this video.