Did it say you needed a firmware update, or that a firmware update was available? I've found that it is rare to actually need a firmware update, and Victron's continual updates are often (mostly?) to add or correct features that aren't very relevant to boats. In fact, Victron specifically recommends NOT upgrading firmware if the unit is operating fully as is.
Otherwise, installing a firmware update is dead simple - load the file, press update, and wait.
Mark
Otherwise, installing a firmware update is dead simple - load the file, press update, and wait.
Mark