What are the basic intial steps for me to use my exchange model and uploading my xmi file inorder to utilize the NIEM exchange mapping tool?

In ArgoUML:
- Create a project in ArgoUML  and save it as XMI compressed project file (.zip) instead of as a zargo or uml output.
- Create a class diagram, adding new classes to it, as well as attributes including the types (depending on your needs).
- Save the entire project as stated above after creating the classes.
- Click on File and select export XMI...
- Save the file as XML Metadata Interchange (*.xmi) type

In NIEM Mapping tool:
- Click on create an exchange to upload the xmi file
- Click on save and map
- Click the name of the exchange model below the label "Exchange Models." The tool will forward you to the next step, where you may select a data element to map. This will pull out the data elements created in the exchange model.
- Click on search, NIEM for a component with a name similar to a data element, or you may make a note about a data element.
- Map the data element to any of the NIEM components listed by clicking on map beside the NIEM component
- Choose the mapping category i.e. equivalent or partial e.t.c., or make notes and click on save.
- After you have mapped a data element, you may generate mapping reports, wantlists, and schemas by following the instructions listed under the label "Additional Help".
- This should generate your needed artifacts and you can make changes to them as well.

NIEM Exchange Mapping Tool:

ArgoUML: http://argouml.tigris.org/