You can uninstall the Web Server Plug-ins using the Installation Manager command line.
imcl.exe uninstall com.ibm.websphere.PLG.v85 -installationDirectory installation_directory
./imcl uninstall com.ibm.websphere.PLG.v85 -installationDirectory installation_directory
Go to the IBM® Installation Manager Version 1.6 Information Center or the IBM Installation Manager Version 1.5 Information Center for more information.