Gen 5 receiver Upgrade . For information on how to ship your Original T36 Receiver back to TommyBuilt Tactical, we only need the upper or barrled upper and the lower, we will destroy the upper and ATF comes here to confirm, the lower will be modified to fit the new receiver and sent back with your new Gen 5 upper to your FFL. If you can not remove the stock or brace we will take care of it. If you need NFA engraving we will add that at no charge, just add it in the notes or send an email with your order number. VERY IMPORTANT!!! make sure the billing and shipping address match for your CC or it will kick it back as fraud, We will ship it to your FFL only Also check your spam, our emails are often blocked so if you do not receive an order number email its likely in your spam, thanks ... please refer to this page.