If you bought Mastermind's Manual on RPGNow.com:
You should receive instructions soon on how to access the updated file.
If you bought Mastermind's Manual in our Green Ronin Online Store:
To access your updated PDF, please refer to the email message you originally received with the link and login information. Just click the link, log in, and the file you download will be the updated one. If you deleted that message (tsk, tsk!) please send an inquiry to pdfsupport [at] greenronin [dot] com with your order number and name, and make sure to write from the same email address you used in our Green Ronin Online Store when you purchased Mastermind's Manual.
Thanks for your support!
And in case you haven't yet picked up the Mastermind's Manual PDF, new purchases will of course also deliver the updated file.