Sun Microsystems SunPCi 1.1 Guide D'installation page 21

Removing the Patch (Solaris 2.6 and Solaris 7)
If you have a SunPCi upgrade patch installed and you are running Solaris 2.6,
Solaris 7, or above, follow this procedure to remove the patch. If you do not have a
patch installed, proceed directly to "Installing the SunPCi 1.1 Package" on page en-
18.
1. Open a command (terminal) window on the Solaris desktop.
2. Enter the following command:
% showrev -p | grep SUNWspci
This command shows the version number of the patch, the version number of the
patch that it replaced, and the name of the patch. If you do not have a patch
installed, the showrev command will produce no result; it simply returns the
system prompt.
3. Become superuser on your system.
Enter the following command:
% su
Enter the root password. The superuser prompt (for example, #) appears. If you do
not know the password, see your system administrator.
4. Type the cd command at the superuser prompt to change to the patch directory.
# cd /var/sadm/patch
5. Enter the following command to run the backoutpatch script. Substitute the
revision number of your previously installed patch for xxxxxx-xx.
# ./patchrm xxxxxx-xx
If the script executes successfully, it displays the following message:
Patch xxxxxx-xx has been removed.
If the script returns an error message, refer to the README file included with the
patch.
SunPCi Hardware and Software Installation en-17