How to update web reference in visual studio without access to the web service server

Question

We have a old app that uses some webservices to communicate with another server. only the app server has access to the webservice server. recently the owner of the webservice have made some changes to the webservices. Now we have to update our web references in the application. However, since our dev machine doesn't have any access to the webservice server, we can't just update the reference by right clicking and selecting "Update web reference". We have tried to create a dummy project in the app server, adding the reference to the dummy project, and then copying the wsdl/disco file to the actual dev environment. But it's giving error when we try to build the project. So, how can we update the web reference in dev environment network access to the web service server?