look on the side of the gun you will see a small screw on the right side between the cylinder and the trigger . take the screw out and there is a pin that will fall out when turn it over , do not lose it. flip the cylinder out and the swing arm will slide forward so that the whole cylinder will come out . then you can take ejector out and clean it
In my opinion no! The cylinder length of the 38 special would be shorter than the cylinder length of a .357 Magnum.
It is possible
Best left to a gunsmith
1970
50-550 usd
Does not exist.
Cartridge
Yes they have made them.
357 Magnum
Smith and Wesson 500 magnum revolver
1980
You take it to a gunmsith.