It is a job you can do yorself as others have said. The guy referred to whose engine blew up after he had reassembled everything was very unlucky. Some lunatic in the past had altered the alignment of one of the camshafts, and put a new mark on it. He used the old factory mark, and that was the cause of the tragedy. Highly inlikely to happen to you, but just check this before you remove the belt !!

KP