I assume you mean the cards are physicaly installed all ready and you want to install the drivers? If you are running Solaris 10, you should have everything you need. If Solaris 8-9 then you need the Sun SAN Foundation 1.4.xx installed. You can download it off the sun downloads site.
(1GB HBAs will work with Solaris 9, 2GB HBA's seen SAN 1.4.xx)