How do you drain the engine block of antifreeze if you do not have a engine block drain plug? I need to get the antifreeze and water out of it because I am going to use “Barr’s leak head gasket repair” and need the engine block totally empty.
I would suggest than unless that car (unknown make, model, year, color and mileage) is a real junker that you should not use that stuff. Get it fixed right. That is a case where the fix can be worse than the original problem.
If you insist, you may be able to remove a radiator hose.
You could take off the lower hose, take out the thermostat and try a wet/dry vac.