When you install, turn from back to front facing, replace etc. a car seat or booster do you do it completely yourself or do you have a licensed car seat specialist (in our town that’s police) do it and/or assist you or check it for safety? I have always done the latter. However, I want to upgrade my 16 MO to a larger seat (currently in infant) and 4YO to a booster. I’d like to do it myself but I worry about it being correct and safe.