It is best to change your oil after the engine has been off over night. This allows all the oil to drain down to the crank case. A warm or hot engine will still have oil up in the engine which will take hours to drain completely. Also you won't run the risk of getting burned.

Pull the drain plug and let the oil drain until the oil is only dripping out about 1 drop every 5 or 6 seconds. At this point the oil is purged about as much as can be expected.

Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety. Benjamin Franklin, US author, diplomat, inventor, physicist, politician, & printer (1706 - 1790)