Using the ESX Console press F2 then Login and select the Troubleshooting menu.
Enable ESXi Shell selecting the option and pressing enter.
Now pres Alt-F1 on the keyboard.
You be presented with a Linux command prompt. Login wit root privileges and run this commands:
Scroll down the file or search for “name” using Esc, /name, Enter and keep hitting "n" until you find the vSwitch section you want to change.
Change the word by hitting Insert, writing the right name, and then hitting Escape.
/net/vswitch/child/name = “vSwitch3“
Now write :wq! and hit Enter to save the changes and exit.
Press Alt-F2 and disable the ESXi Shell.
Restart the host.