FYI in many places (probably not California) the permitting process is dead easy. In my jurisdiction in South Carolina it's all online (from filing to calling in inspections) and cost something like $25. The folks in the building office are there to serve citizens. While they'll not tell you how to do the work, they'll certainly help you through the process and in my experience and are generally happy to tell you what does and does not need a permit.
While it's technically and mechanically fairly easy to do electrical work (I've pulled permits and done a couple 14-50s and complete building rough/final with "YouTube training" and been told it was better than many tradepeople by the inspectors) it can and will kill you, especially when you're working with 240V/50A. Every homeowner should have a "contactless electrical tester," which looks like a fat fountain pen and beeps when placed next to a live electrical circuit. It will set you back something like $14 for a good one and can save your life. At a minimum if you're even thinking of doing this yourself buy one of these and don't touch ANYTHING without putting the tester next to it and making sure it's been turned off. Never test a live circuit holding probes in both your hands, since a short will go through your chest and heart. Use both probes in one hand so if you mess up you'll hopefully only lose an arm.
