I managed to tame one using a high level beelzebufo (not too much higher level than the kapro otherwise its attacks will kill it, alternatively you could probably use a lower level one and level all points into health) because my frog was able to knock it unconcious. I could have tamed the other one that was in the area, but it was busy knawing at my legs and I panicked.
So while you're being lovingly caressed, have your beelzebufo on neutral and both you whacking it with a bat and your frogs attacks *should* knock it out before you die. Just make sure no other sarcos or anything are in the area. (Protip: jump while mounted on your froggo and you'll dodge a kapros lunge. It'll give you enough time to at least put a tranq dart/arrow into it to get the ball rolling)
If you ride a stego in the swamp, you won’t get caught by the kapro(they just sorta slam and bite the stego instead), so long as you bring some tranq arrows in a crossbow, you can tame one easily(many swamp creatures drop prime meat). Just make sure you use a combo of passive, neutral, and knock back to escort back(I play mobile, but picking one up can also work).