Simply use a bola so it can't run because they run pretty fast. Use either a sling shot or tranq to knock it out. Once tamed put gathered stimberries and mejo or tintoberries on it and force feed the stimberries and it will poop for days. Usually 100 stims equal 20-25 poops. Best to have a dung beetle to make fertilizer as well :)
These guys are pretty easy to tame. I normally find them by the swamps and it’s quite dangerous there so get a club and hit it in the direction out of the swamp then try to corner it into some rocks or something then knock it out and feed it tinto berries, tamed pretty quick for me. Get a LOT of berries if you are planning on taming one of these guys.
Super East to tame, I just cornered it and clubbed it till it was unconscious. Then I feed it, that was the hardest part. I had to harvest berries while taming, so be preped if you want to tame one of these suckers, or just knockout near lots of bushes.