It seems a bit difficult for you if you install a solar water heater all by yourself, as many factors needs to be considered before installation. You need to have the bacis information of the local weather, you local solar insolation (it means the amount of sunlight that you'll be receiving), the standard of safety and the basic requirement of local apartment.
To consider all these things, a professional solar water heater installer is always advised by experts. However, if you have a proper knowledge and understanding of all the above mentioned things, you are qualified for DIY solar water heater installation.
Here is the actual procedure for it.
This is a list of all the materials required for the procedure of installation.