Setting properties of VMs in a vApp

I have a few vApps with 25 VMs each in vCloud Director and would like to set a few properties to on / off with PowerCLI as the gui is a mission. These options include:

Set "Enable guest customization" to yes, "Change SID" to no and "Password Reset" to no.

I looked at the avaliable command-lets with "get-command -Module vmware.vimautomation.cloud" but I see nothing that allows manipulation of a VMs in a vApp.

Would I be able to make these changes with PowerCLI?

Thanks!