How to reread wt.properties file in Eclipse project

How to reread wt.properties file in eclipse project? I have two Windchill servers. 1-st is the production server and 2-nd is the server for developing. First I have copied wt.properties file from production server and Eclipse worked fine with the production server. Then I copied wt.properties from dev server, but when I start my project eclipse still working with the production server. What can i do for rereading wt.properties file?