Once you have exported your requirements from an RQM to a Team System project, it is possible that you will continue to edit the details of these items (by adding or editing a detailed description, changing the status, or any of the other available properties). To cascade these edits to your requirements work items held with a Team System project, simply select (or click the Update Work Items tool).
The Update tool refreshes all the requirement work items exported to any number of Team System projects. Note that it does not export any new requirements (this requires that you use the Export tool) and that it does not update any changes made in requirement work items to their counterparts in the RQM.