Bari & Christi Stockton

Can anybody out there tell me how to go about upgrading road categories? I was told by Candi that I need documentation to upgrade (which is posted on the web site). I have said that I want an upgrade to Candi only to get the reply about documentation and the upgrade rules are very vague. The rules only state what the criteria is, not how to go about said upgrade.
Any info would be greatly appreciated.
Bari Stockton