Unpack the VM archive until you get to the disk image (.vmkd .qcow2 etc and .ovf files)
Transfer the files to the Proxmox Server into somewhere like /var/lib/vz/template/
ssh into the server (or from the shell in the web interface) and create a new VM that has the correct specifications.
CD /var/lib/vz/template and run the following depending on the original disk file:
KVM: qm importdisk ‘vm-id’ /var/lib/vz/template/’disk name.qcow2′ External (location)
For an OVF first unpack it, extract the .vmkd file and upload it, then do the VMWARE stuff.
VMWARE: convert first and then import
qemu-img convert -f vmdk -O qcow2 ‘vmkd-disk-name’.vmdk ‘qcow2-disk-name’.qcow2
qm importdisk ‘vm-id’ /var/lib/vz/template/’disk name.qcow2′ External (location)
There should now be a unused disk against that machine that can be attached to it, don’t forget to add the new disk to the boot order.
