How to switch LAN (mgmt interface) from copper to sfp+?

[alto]

I currently have my management interface (igb0) connected with copper cat6 to my switch, this is also the parent interface of all my vlans. I want to change this to run over sfp+ though, i.e. to use interface ax0 instead. But what is the procedure to do this so that I don't completely lock myself out of the router if I change the management interface device from igb0 to ax0 and something doesn't work?