Lance,
To make the shutoff job 100x easier, remove the ALDA. Photos with instructions are at this URL:
http://www.meimann.com/images/mercedes/OM603_injection/
You should also replace the O-ring for the shutoff pod at the same time (must order separately!). The MOST important thing to do is apply vacuum to the old pod and watch the metal external shutoff/stop lever travel. When you install the new pod, apply vacuum to that BEFORE you start the engine. Make sure the lever moves ALL the way up and down, same as the old one. Failure to do so can result in a runaway engine and a $5000 doorstop. Ask Larry, or search for his thread on this forum. This job is simple enough but you MUST be careful to verify installation (which requires a vacuum source, like a MityVac). Don't skip this step. Please.
Good luck,