Removing a webserver from WebSphere

We used to allow employees to get into self-service directly from the internet, without first going through our company portal.  We have now stopped that.  But the webserver that we used (for this purpose only) is still "hooked in" to our production set-up in WebSphere.

What I need to do is remove this server from WebSphere.  I am not especially familiar adding/removing servers from WebSphere. 

When I go into WebSphere, and look at the "Middleware servers" page, I see the button that says "Delete".  Looks tempting, but I'm sure it's not that easy. 

Any advice on how to proceed, where to go for documentation - anything?

Thanks so much for any thoughts or advice.

Dawn