Yopu should be fine making sure the key is out of the ignition so the SRS module doesn't get powered up. Do your seat mod. Make sure the SRS cable is plugged back in. If the SRS module doesn't get powered up, it won't see the "fault". You can also go to
www.hondatechinfo.com, pay a 3 day subscription, and read the procedures there to be sure what you are getting into.