How to change NIC's speed on Solaris 10

Hi,
How to change NIC's speed on Solaris 10 which is installed on Oracle T3-1 server.

# dladm show-dev
vsw0            link: up        speed: 1000  Mbps       duplex: full
vsw1            link: up        speed: 0     Mbps       duplex: half
vsw2            link: up        speed: 1000  Mbps       duplex: full
vsw3            link: up        speed: 1000  Mbps       duplex: full
vsw4            link: up        speed: 100   Mbps       duplex: full
vsw5            link: up        speed: 100   Mbps       duplex: full
vsw6            link: up        speed: 1000  Mbps       duplex: full
vsw7            link: up        speed: 1000  Mbps       duplex: full
vsw8            link: up        speed: 100   Mbps       duplex: full
vsw9            link: up        speed: 100   Mbps       duplex: full
nxge0           link: up        speed: 1000  Mbps       duplex: full
nxge1           link: up        speed: 1000  Mbps       duplex: full