I don’t think I have ever needed to do this in a production environment, but it is helpful for training/teaching when running virtual ESXi hosts in the lab.
First you need to enable and start Remote Tech Support (SSH). This is done for the ESXi Host in Configuration -> Software -> Security Profile
Use an SSH client (putty) to connect to the ESXi host.
Once logged in simply run dcui
~ # dcui
To exit DCUI and return to the prompt use CTRL-C