I used to play a game called Tokyo Jungle, in it you can play various animals in a humanless version of Tokyo. The main goal of the game is to explore the city and survive as long as you can while eating plants or animals your animal likes. This game taught me that larger animals need more calories to survive, as my runs with the alligator would end the quickest, where with the smaller animals I could play for longer. I just fact checked myself and elephants eat about 330-375 pounds of food per day, and this makes sense, the larger the biology, the more cells they have, the more cells they have, the more energy they need to keep those cells alive.

Since a t-rex is much bigger than an elephant, I'd imagine they would need an insane amount of calories per day to survive. In a starvation contest, a human would win. All you would have to do is wait for the lethargy of starvation to set in, and then when it falls asleep try to puncture an artery or slice tendons to immobilize the dino. The idea is that it would be so starved that even if it woke up, it wouldn't have the coordination to immediately eat you, you may even have a comfortable window of time to seek shelter in the case that things go sideways. Or if you wanted to play it safe you could just wait for the t-rex to expire from starvation, but you'd most likely be feeling like shit by the end of that.