What is the correct way to kill a vncsession in linux?

$ cat /etc/xrdp/xrdp.ini

$ cat /etc/xrdp/sesman.ini
[Logging]
LogFile=/var/log/xrdp-sesman.log

$ rm -rf ~/.cache/*
$ ls -la .xsession
$ ls -la .ICEauthority
$ cat ~/.cache/upstart/startxfce4.log

$ ps ax | grep vnc
25697 ?        S     55:38 Xvnc4 :1 [...]
[...]
30481 ?        S     17:57 Xvnc4 :2 [...]
$ vncserver -kill :1
or
$ kill 25697