Just increase your pledge (after shipping) by the cost of the add-ons you want ($20 for sleeves for example).
So, if you order the $75 tier in the USA with sleeves, you would pledge $106 ($75 + $11 shipping + $20).
To do this click on the "Manage Your Pledge" button, click on "Change Your Pledge", and increase the amount by $20.
A month or two after this campaign ends, we will email out the pledge manager. You will get to specify which add-ons you want in that pledge manager.