There are two ways…
The deb way
Download the archive with deb files and extract the archive, and yes, I'm sure
tar xf VNC-5.2.3-Linux-x64-DEB.tar.gz
Install via
sudo dpkg -i VNC-Server-5.2.3-Linux-x64.deb VNC-Viewer-5.2.3-Linux-x64.deb
And remove the packages. This will also remove the files from the installation via ./vncinstall
sudo apt-get purge realvnc-vnc-server
sudo apt-get purge realvnc-vnc-viewer
The script way
There is no script to remove the installed files. But you could use this, tested on my own system:
#!/bin/bash
sudo rm /usr/share/man/man1/vncviewer.1
sudo rm /usr/share/man/man1/vncaddrbook.1
sudo rm /usr/share/man/man1/vncserver-x11.1
sudo rm /usr/share/man/man1/Xvnc.1
sudo rm /usr/share/man/man1/vncserver-virtual.1
sudo rm /usr/share/man/man1/vncserver-virtuald.1
sudo rm /usr/share/man/man1/vncserver-x11-serviced.1
sudo rm /usr/share/man/man1/vncpasswd.1
sudo rm /usr/share/man/man1/vnclicense.1
sudo rm /usr/share/man/man1/vncinitconfig.1
sudo rm /etc/pam.d/vncserver
sudo rm -r /root/.vnc
sudo rm -r /usr/lib/vnc
sudo rm -r /usr/share/vnc
sudo rm -r /usr/lib/cups/vnc
sudo rm -r /usr/lib/cups/backend/vnc
sudo rm -r /usr/share/vnc
sudo rm -r /etc/vnc
for f in vncviewer vncaddrbook vncserver-x11 vncserver-x11-core Xvnc Xvnc-core \
vncserverui vncserver-virtual vncserver-virtuald \
vncserver-x11-serviced vncpasswd vnclicense vnclicensewiz \
vnclicensehelper vncpipehelper vncinitconfig vncserver; do
sudo rm "/usr/bin/$f"
done