Step 1. Purchase a year plan from options found here.
Step 2. Once your device arrives retrieve the SN# from the product box
Step 3. Visit https://go.boom.us Choose "Activate my BOOMfi"
Step 4. Enter your SN# and account creation info. If a year was purchased already with the device this plan should already be showing with no payment due. The plans each run 1 month at a time though so when activating you will have a chance to purchase the extra for the current month or use your purchased time right away.
-- If you choose to use the months you have already purchased you may lose some days. EX. if you activate on the 16th and do not purchase a prorated month to cover it will use an entire month to cover those days.
Step 5. After your activation is complete record your Account Number and power on your device. You are ready to go!