I'm using GWT 2.4 & Eclipse Juno. GWT is installed using the instructions at https://developers.google.com/web-toolkit/usingeclipse.
I'd like to try GWT 2.5.
How do I upgrade from GWT 2.4 to 2.5?
Currently, GWT 2.5 is only available as a Release Candidate, and as such is not delivered via the usual Eclipse update site yet. However, it's easy to use Eclipse with any GWT version:
- Download the GWT SDK(s) you need from https://developers.google.com/web-toolkit/versions
- Extract it anywhere you like
- In Eclipse Preferences > Google > Web Toolkit, use the "Add..." button and navigate to the GWT SDK directory
Then, in each Eclipse project's properties page (Project > Properties > Google > Web Toolkit), you can choose one of your installed SDKs.
来源：https://stackoverflow.com/questions/11691575/how-do-upgrade-to-gwt-2-5-in-eclipse