Disconnect the connectors from the passenger's under-dash fuse/relay box (A).
Loose the mounting bolt from the lower side of passenger's under-dash fuse/relay box.
Remove the mounting bolt from the upper side of passenger's under-dash fuse/relay box, and remove the passenger's under-dash fuse/relay box.
Installation
Connect the connectors to the passenger's under-dash fuse/relay box, then install the passenger's under-dash fuse/relay box in the reverse order of removal.
Install the removed parts in the reverse order of removal.