Ok, done. Worked as expected:
pvecm delnode pve1
rm -rf /etc/pve/nodes/pve1
Then shutdown the node, Install a new one with the same name and IP nr.
When I added that one to the cluster I noticed that my SDN network had a state of pending for this node. So I needed to apply the SDN configuration again. Then the status cleared.
Thanks for all the help guys,
Albert