First, please note that ModeShape 4.2.0.Final only works with Wildfly 8.2.0.Final.
modeshape-explorer is/should be deployed by the ModeShape modules automatically when you start the server up. The only thing you need to make sure is that the repository configuration has the following section:
You should not attempt to deploy the explorer application by hand and/or in your own application/modules.
Awesome, thanks. Just for clarification ModeShape 4.1.0.Final is the version for Wildfly 8.1.0.Final?
That's correct: 4.1.0.Final will work with WF 8.1.0.Final, but 4.2.0.Final will only work with WF 8.2.0.Final because of the fact that 8.1.0.Final contains a beta version of picketbox.