Sorry to be the bearer of bad news but if it is one of the stars that can not be exposed to air then there is no hope. You`ll know because he will get wrinkly and fall apart. What kind of star is that. I`ve never seen that kind before.
I doubt there's a way to ensure it was never exposed to air in the catching/selling process. Also most stars like this need huge tanks that are very mature to survive. If your friend has 2 I hope they have a few hundred gallons and lbs of LR/sand.