Use the Eclipse update manager to install Findbugs from the Findbugs update site http://findbugs.cs.umd.edu/eclipse .

After installing findbugs you can activate findbugs for your project via the properties of your project and select FindBugs -> Run FindBugs automatically.

To see the Findbugs errors, select Window->Show View -> Other. The Findbugs errors will be displayed in this view.