If you are not familiar with wsadmin, check out my article IBM WebSphere - Getting Started with wsadmin.

Here is an example of how to list the web servers that have been added to your WebSphere deployment manager (dmgr) using wsadmin.

~]$ /opt/WebSphere/AppServer/profiles/your_profile/bin/wsadmin.sh -lang jython -c "print AdminTask.listServers('[-serverType WEB_SERVER ]')"
WASX7209I: Connected to process "dmgr" on node your_node using SOAP connector;  The type of process is: DeploymentManager
WebServer01(cells/your_cell/nodes/your_node/servers/your_server|server.xml)
WebServer02(cells/your_cell/nodes/your_node/servers/your_server|server.xml)
WebServer03(cells/your_cell/nodes/your_node/servers/your_server|server.xml)

And then the following AdminTask can be used to delete one of the web servers. This is kind of strange because if this command is successful, no output will be returned.

/opt/WebSphere/AppServer/profiles/your_profile/bin/wsadmin.sh -lang jython -c "print AdminTask.deleteWebServer('[-serverName WebServer01 -nodeName Node01 ]')"