The key to successful replacement of the lower front timing cover (Stirndeckel) gasket on the M104 is removing the dowel pins (and I think most mechanics include a heavy dose of RTV sealant as well). If you don't remove the dowels, you have a hard time keeping the gasket in place while you reinstall the cover.
It's a straightforward job, but a several hour job with removing the valve cover etc to get access, if my memory serves me correctly.

__________________
Prost!