It is great to hear that you are enjoying your font and now want to increase the number of people/computers who can access this. In order to do this, you will need to purchase a new license for the additional desktop users. These two (or however many) licenses together will cover you for the 10 users that you now require.
We do not offer the option to officially cancel this initial paperwork and therefore 'upgrade' the license, this would add too many additional fees that neither of us want. Instead you can simply purchase a new license for the additional users to ensure that you are covered (and we do recommend that you consider future growth to keep it as cost effective as possible for you and your team, maybe adding a few extra users now, would save you a little overall).