On a recommendation I bought a used Lowe Alpine Contour IV 90+15 for my winter pack, due to none of my others being big enough for my -25F bag and other gear. The pack has aluminum stays, and I’m looking for the procedure to contour the stays to my back. They’re in long pockets on the edges of the pack’s back and slide in & out easily so I’m guessing it’s a matter of pulling them out and having someone press them against your back. Am I right? Or can they be shaped by carrying a loaded pack?