Can you expand on the requirement? You want to do this via API like Sudeep has suggested? Or by using some type of utility? Or something else?
There are existing articles on using a command line tool. It generates some SQL code. But the SQL code it generates will change the type of all WTPart objects. You'll need to modify the SQL for only that single WTPart if you choose this method.
https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS7287
https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS52368