you will have to have remote console access to your ESX Host, but you can try
esxcfg-vswitch -L vmnic0 vSwitch0
here's some good tips as well
Thanks for the syntax and pointer. I had to recreate the vswitch0 first and then execute the cmd you provide, then execute esxcfg-vswif -r vswif0, which i found on the link you provided. Thanks a million!
cheers,
norcalwaverider