NTA doesn't need it's own server, it will have it's own database server. As such, don't uninstall it from the NPM server, simply designate a server to be the NTA Fastbit DB server (I wouldn't recommend using either the NPM or SQL server for this). You would want to move NCM onto the same server as NPM, then you could actually use that server for the NTA DB server if it's within the requirements. I'd just run the upgrade like this:
Upgrade NPM
Install NTA on the new NTA DB Server to install the fastbit database
Upgrade NTA and make sure to point to the new NTA DB Server in the configuration wizard
Install NCM on new server and upgrade to the latest revision
Upgrade IPAM
Upgrade VNQM