You may have to have it reset using the Honda diagnostic tool, or it should be possible with one of the professional multi-brand diagnostic systems like Delphi or Snap-On, used by many smaller garages. Of course, something may have been disturbed during the work, and in that case you will need a code-read in any case, to work out what's going on.
For future reference, you must deactivate the airbag system, before disconnecting any airbags or seat pre-tensioners. Not only will this prevent spurious SRS faults, it also minimises the risks of accidental activation - which can be very dangerous indeed.
With the keys removed from the ignition, disconnect the starting battery, then wait at least 3 minutes - this is to allow the energy stored in the airbag backup capacitors to dissipate. You must do this before starting any work involving the SRS system. Store any removed airbags face up, away from the work area. Reconnect all the airbags before reconnecting the battery.
