If you backed up your presets, that is merely an offline copy on your computer. They remain on the unit.
If you didn't actually remove them (or delete them) from the unit, there is nothing to "reload" -- your presets remain as they were saved (in previous FW).
However, per the
release notes certain parameters are automatically reset when they are recalled into active memory. If you didn't change those in your tweaked presets, then there isn't anything to do except audition them to make sure you like them with the new FW (and optionally resave -- but then you can't use those presets in a prior FW, so make sure you have a backup from the previous FW!).
If you did change one or more of those parameters you'd have to manually set them back.