conf t
Switch(config)#interface fastEthernet 0/2
Switch(config-if)#no switchport mode
Switch(config-if)#no switchport mode trunk Switch(config-if)#exit
%SYS-5-CONFIG_I: Configured from console by console
Switch#wr Building configuration...
Anexo 63663Anexo 63664
Em fastEthernet 0/2 você coloca a interface que quer tirar do trunk.