The 5-0 is not that complicated of a trick after you can land 50-50's. Its easier for most people to try then Frontside. 5-0's are harder to land on circular rails so try them on a box, ledge, or square rail to start. Come to the obstacle at a small angle and ollie up like you would for a 50-50 only put your pressure on your back foot so you land in 5-0 kinda like a manaul on the rail. Continue grinding the rail until the end when you want to press down with your front foot so you can land flat and roll away.