First, get shell access on the console: Howto: ESXi shell access

Then:

1. Type “vi /etc/inetd.conf” and press “enter”.

2. Locate the line that starts with “#ssh     stream  tcp     nowait  root    /sbin/dropbearmulti…….”

3. Move the marker over the “#” and press “x”.

4. Press “Escape” and write “:wq”, then press “enter”.

5. Type “/sbin/services.sh restart” and press “Enter”. Note: If you are running ESXi 3.5 Update 2, the services.sh no longer restarts the inetd process. You will have to manually kill the inetd process, in order to restart it and enable ssh access without a reboot.  Type “ps | grep inetd” and press “enter”. You will then see something similiar to “1289 1289 busybox              inetd”. Then write “kill -HUP 1289″, and remember to write the number “ps | grep inetd” returns to you!