Rex kidnap strategy for dummies

Min. Needed: (lvl 50) Crossbow, 50+ tranq arrows, giant bear trap, wooden/stone structures, a strong saddled tame (solid Carno or better), luck

Find the Rex, place down a trap and then place 2 or more foundations with doorways like a segregated border wall

Ragebait the Rex and shoot arrows at it to make it chase you

Jump over the trap and stand right in front of it, make the Rex get stuck

Magdump the Rex until it falls over and feed it prime meat, which you can get by killing a nearby stego or bigahh dino with your tame (bringing some is also optional; but ts spoils fast)

Wait a few minutes and feed it a few dozen narcotics, and Now you have a Rex (you get to wait 2 months to unlock the saddle)