How to do manual task assignment

The Task Management Service has the following interface method:

public void reassign(String taskID, AuthIdentifierSet users, AuthIdentifierSet roles, TaskState state, String participantToken) throws Exception

That can be used to reassign a task to different users, different roles.
Once a task is in someone's inbox, calling this method through the TMS Axis Webservice, will result in the task being accessible to a different set of users, than what was originally planned during design time.

The TMS WSDL decribe the reassign request as:

<xsd:element name="reassignRequest">
  <xsd:complexType>
    <xsd:sequence>
      <xsd:element name="taskId" type="xsd:string" minOccurs="1" maxOccurs="1" />
      <xsd:element name="userOwner" type="xsd:string" minOccurs="0" maxOccurs="unbounded" />
      <xsd:element name="roleOwner" type="xsd:string" minOccurs="0" maxOccurs="unbounded" />
      <xsd:element name="taskState" type="xsd:string" minOccurs="1" maxOccurs="1" />
      <xsd:element name="participantToken" type="xsd:string" minOccurs="1" maxOccurs="1" />
    </xsd:sequence>
  </xsd:complexType>
</xsd:element>

The old assignable users referenced for this task will be completely replaced by the new ones.
Reassign has a very extensive test case on its own, that can be used as an example.