Retrieve Windchill role of a given user into ThingWorx

I need to retrieve some data from Windchill into ThingWorx. To begin with, am trying to fetch the Windchill role of a given user, into ThingWorx either using REST services or InfoEngine Tasks (webject xml). But the REST APIs found in Windchill documentation have less or no samples. Please help us.

Thanks

Avinash