as a master user, go to Tools|Configure|License Manager, then to the Net-Update tab. There, check the 'Update Registration Information' box and flip over to the Registration tab. With that box checked, you can now change/modify your info.
Note that this doesn't change the company name/info associated with your Maintenance contract with HEAT/Ivanti. For that, you'd want to contact the customer care department who can supply the relevant forms and whatnot.