When an Orderer for some reason isn't able to finish a project, the role can be handed over to a new person. Since a project requires an Orderer, it's most important to hand over the position before becoming absent.
To change the Orderer in a project, navigate to the Project menu and select the 'Change Orderer' option.

Or you can change the Orderer here:
Watch this short clip to see how to change Project Orderer:
Written by Fredrik Hultin.