FortiGate LAN Ports

We have a Fortigate 200B Ports 1-8 are setup as LAN but My understanding is 1 - 8 are 10/100 ports only? How can I easily add a Gigabit port (10 - 16) (9 is WAN) to the LAN Group?
FortiOS 5.2.13


That is an older model and I have not very familiar with it, might want to try their forums.