I'm trying to replace the inner tube in the tire of a "Radio Flyer"
child's wagon.

I've removed the wheel from the wagon, worked the tire off one side of
the rim and removed the old inner tube.

The new inner tube is twisting when I work it into the tire. Should I
partially inflate the new inner tube first?

Do I put the valve stem through the hole in the rim before working the
rest of the inner tube into the tire?

Once I get the inner tube into the tire, how do I get the tire back
onto the rim?