I have Astrill VPN installed. I have had trouble. They advise me to uninstall the old version and then install the newer version.

Astrill is not installed via Ubuntu Software Centre.

How do I get rid of Astrill??

This is part of the output of dpkg --list It does not show Astrill.
ii apturl-common 0.5.1ubuntu3 install packages using the apt protocol - common data
ii aspell 0.60.7~20110707-1 GNU Aspell spell-checker
ii aspell-en 6.0-0-6ubuntu2 English dictionary for GNU Aspell
ii at 3.1.13-1ubuntu1 Delayed job execution and batch processing
ii at-spi2-core 2.4.2-0ubuntu0.1 Assistive Technology Service Provider Interface (dbus core)
ii avahi-autoipd 0.6.30-5ubuntu2 Avahi IPv4LL network address configuration daemon
ii avahi-daemon 0.6.30-5ubuntu2

pedro@peterpu:~$ sudo apt-get remove astrill
[sudo] password for pedro:
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package astrill
pedro@peterpu:~$

You could try re-installing the package, then try to remove it. I tried this on a VM (Ubuntu 13.10) and worked fine:

1. Downloaded the deb from astrill's site.
2. Opened and installed the deb with Ubuntu Software Center.
3. Removed it using Ubuntu Software Center, or the command line.

Thanks! I did just that. The first time I installed Astrill, the package would not install, so I used the cli. That installs it, but does not register it with dpkg. Also, I must have tried to install the 64 bit, and that did not work, which is why I had to use the cli.

This time I did it right I hope, anyway Ubuntu Software Centre installed it fine, so anytime I want to uninstall, I can.

The Chinese Govt. does not like Astrill!