The ESXi 5.1.0 patch documentation (http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2043968) describes that one can use VMware Update Manager to install the patches. It says "For details, see the Installing and Administering VMware vSphere Update Manager.". It's just that there is no link pointing to where to get the installer. And if I search VMware web for "Update Manager" then I get a gazillion hits with documentaiton and discussions for it, but no download link.
Is is embedded in some other installer or ... ?