There are corresponding rings on the engine to designate which goes where.Just match the number of rings.You may have to clean up the engine a little near the hole for the tensioner.Be careful not to get any dirt in the hole.
Here is a helpful diagram:
http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/Gp1800.pdf