How to upgrade ESXi 5.x to the latest ESXi 5.5 Update 1?

1. Download the latest patch from https://www.vmware.com/patchmgr/findPatch.portal

esxi5.5u1

2. Upload this file to the datastore visible by your ESXi host.

esxi5.5u1-2-590x375

3. Put your host in maintenance mode (right click > enter maintenance mode) and connect via putty. Note that SSh must be enabled. (configuration > security profile > properties > ssh). Now run this command to update the host:

esxcli software vib update -d /vmfs/volumes//update-from-esxi5.5-5.5_update01.zip

Reboot your host and exit maintenance mode.