Go buy a coolant tester and use it to ensure the coolant is able to withstand the coldest temperatures for your area or more.

Plug in the block heater.

You are going to create a bigger mess and stink messing around with pumps and removal. I would turn the fuel off and run the carb out if equipped then close the tank vent if possible.

I think YouTube killed many of the forums when it comes to repairing things. It’s quick and easy to find someone addressing the problem you have without the browsing. I’m out as soon as the mechanic picks up a claw hammer. No respect for those guys.