I have never worked with plaster either and can't give you good advice in this case. It would be wiser to just hire a specialist for the job. It will be much faster and without unnecessary hassle. Recently, I also had a renovation at home, and I updated all the electrics and, at the same time, changed ordinary light bulbs to smart bulbs. I didn't even try to do it myself because I didn't understand anything in electrics. It's not that hard to change a light bulb. I do it. However, when more serious problems arise, such as changing wires, I immediately call a specialist. This is much smarter than trying to do it yourself without the necessary knowledge.