Whether you want to get an add-on, an unlocked stretch goal, or another Modular Dungeon Set don't worry the process is easy. All you need to do is click your selected reward and change the pledge amount to reflect the products that you want. For Modular Dungeon Sets you will need to also add the shipping cost to the price. Here is a list of examples.
If you want these products add this amount to your reward for shipping within the US (check shipping for your country and add that total instead if you are outside of the US):
Aerial Stands - $12
4 Monster Horde Token Sets - $20
8 Monster Horde Token Sets - $40
Squire's Set - $60 + $14 shipping
Rogue's Set - $100 + $14 shipping
Knight's Set - $160 + $14 shipping
Legend's Set - $200 +$19 shipping
Feel free to add as many as you like. When the Kickstarter ends you will have the option to confirm your choices and you will then be charged the pledged amount. We will send out a survey and you can specify what items you wanted from your pledge amount.
Let us know if you need any clarification.