Probably the easiest step. Connect on your ESXi using an SSH client and copy the VEM binaries on the local disk (you can do it with SCP or using wget to retrieve it directly from the VSM web page). The current version of the VEM binaries is cross_cisco-vem-v144-4.2.1.1.5.2.0-3.1.2.vib.
To install it, issue the following command :
esxcli software vib install -v /path/to/cross_cisco-vem-v144-4.2.1.1.5.2.0-3.1.2.vib
..dont’ forget to replace the path to access the vib file.