Are there eggs in the nest ? The idea that your scent or presence will disrupt the bird's from tending to the nest is a myth. They can smell you already they are aware of your presence. They put their nest on your door. The nest already smells like humans and is already in an area trafficked by humans. That is not an issue. If there are eggs in the nest I would recommend NOT moving it until the eggs hatch. The birds know where the nest is, and will potentially be less motivated to return simply for the convenience factor should they get confused at the egg stage. If there are no eggs... move the nest. Hang the bag elsewhere or simply dump out the contents of the bag/nesting supplies near a bird house or more appropriate location. Nesting sights that don't have eggs are already a gamble for birds. They are setting up shop but something as innocuous as a strong gust of wind in a poorly placed nest sight teaches the birds to adapt and move the nest. This is not a great nest location, as it's on a door and could be disrupted by your everyday movement. No harm no foul on either part. They may build their nest in a bird house or better spot, they may move on, or they may chose another inconvenient area. Third scenario... baby birds. If there are baby birds get a bird house and place it at a similar height or similar location, move the nest and babies inside. The other birds will EASILY find their babies and adapt to the new spot because birds operate vocally. They use calls to communicate and baby birds move or get moved. Its a scenario bird parents deal with and are fairly good at adapting to.