To restart a service under solaris, run the scripts under

/lib/svc/method/

This is more or less equivalent to the startup scripts in /etc/init.d/ under linux.

For instance, to restart SSH, run:

/lib/svc/method/sshd restart

You may also want to take a look at svcadm. To restart SSH, you can run

svcadm restart ssh

or

svcadm restart svc:/network/ssh