The supported way to change your hostname is:
The system will halt and on subsequent boot will ask for its name
and other networking parameters again.
You may wish to save a copy of /etc/nsswitch.conf beforehand as
that file is overwritten by the configuration process.
Note that sys-unconfig is not supported on diskless or dataless
workstations. On those, you'll need to edit files by hand. See the
sys-unconfig(1M) for a list of the files that need changing.