I have recently performed something similar to this and yes as simple as adding the 10GbE NICs to the vSwitch and removing the 1GbE NICs. I used this procedure
- Configure 10GbE physical switch including VLAN trunking on ports the ESXi host will connect to, and connect to network.
- Connect ESXi host to 10GbE physical switch
- Add 10GbE NICs to vSwitch
- Remove 1GbE NICs from vSwitch
You may lose a ping to the VMs as they are rerouted from the 1GbE NICs to the 10GbE NICs.
I wasn't using EtherChannel so didn't need to worry about that.
Do all your vmkernel ports and port groups use all of the 1GbE NICs or have you specified some as active and standby for certain ports, e.g. to separate Management and vMotion? Are you using Software iSCSI via this vSwitch, if so then presumably you have set the iSCSI vmkernel port(s) to only use one NIC.