Move back to the passenger side.

Remove the gas tank old gasket. I was able to slide this over the assembly without needing to remove it.

Likewise, install a new gasket (shown in orange here). Again, I could slip this over the existing assembly without much effort.

Clean the mating surface of the gasket before installation to ensure a good seal.

Push the assembly back into place. The assembly has a tab to align it to the proper direction.

Do not make any connections yet.