Click on the 'Haplotree' link (middle left under YDNA heading)
Click on the 'Continue for more information' link under the 'You are Eligible For An Upgrade' heading. If this heading does not appear on your Haplotree tab there is no additional Deep Clade R testing available to you at this time.
Select "Deep Clade" under 'Product' (should already be selected)
Click on the 'Next' link
Complete the remaining payment steps as instructed.