When you travel by train, you can get off at Amsterdam Muiderpoort station. Take the stairs to the left and follow the Insulindeweg. Turn left into the Sumatrastraat. You can find Stayokay Amsterdam Oost at the end of this street.
From Amsterdam Central Station, it's also an option to take Bus 22. You can find this bus at the stop in the opposite of the Victoria Hotel. Ths bus takes you towards the Indische Buurt. Get off at the Javaplein stop and then walk to the Borneostraat. You will find Stayokay Oost after a few minutes on the right.
Another option is to take Tram 14 from central Amsterdam to the Zeeburgerdijk stop. When you get off, walk for a few minutes in the direction of the tram and on your left you will come across Stayokay.