If you already have a earlier verson of the BE-103:

-please just delete the version you have already of the BE-103 and follow the installation guide named -Read Me(installation)
-To delet the plane go into you'r airplanes folder(lacated by default at C:/program files/microsoft games/flight simulator X/sim
objects/airplanes) single click on the Be-103 you and simpily press the delete key.