Have you reviewed the upgrade guides for those products?
vCenter and ESXi - http://pubs.vmware.com/vsphere-55/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-55-upgrade-guide.pdf
VMware View - http://pubs.vmware.com/view-52/topic/com.vmware.ICbase/PDF/horizon-view-52-upgrades.pdf