Trimming and tying your own beef tenderloins is a really easy process. We do quite a few of these each year for various holidays caterings etc.
Start by removing the tenderloin from the cryovac.
Running your finger to the one side you can part out most of the chain. Then slice off the chain and set aside.
Peel off any excess membranes and bits of fat.
Scrape off all membrane and fat from the silverskin.
Insert the tip of your knife under the silverskin and run the knife pointing upwards along the length of the tenderloin to remove.
Turn the tenderloin over and trim hard pockets of fat off. Trim any remaining fats and membrane from the tenderloin.
Flip the tenderloin back over and tuck under the thinnest end so that the thickness of the tenderloin is even.
Tie the roast with butchers twine at 1-2″ intervals.
Ready for the grill. Use the scraps to make stock or grind for some delicious hamburgers.
Check out this excellent video for more tips on trimming & Tying a Beef tenderloin.