Fortunately, the fashion that Plesk is installed lends itself to being uninstalled

with some effort.  You will need to remove all of the psa-* rpms, as well as any

other rpms that may have been installed by plesk.  You will need to remove

the /usr/local/psa directory(if you are on RedHat/Debian), but be careful you do

not remove any VHOST data(mainly seen only on *BSD).



While this is possible, it is not exactly a recommended course of action.  Usually

you will be in much better shape if you preform a complete backup of your system

using the psadump utility, and then host that file off-site.  It would just be a matter

of getting an OS Reload, and restoring your backup after that.