Use the cli
first get the image from the node with the network:
cluster image package get -package url|file
after that finishes start the upgrade:
cluster image update -version 9(tab to get available version)
this should work. It may complain and fail due to the node LIF being down. You may need to use the -ignore-validation-warning flag to bypass any issues. Run without the flag first to be sure
use the man pages for command assistance
man cluster image get
man cluster image update