Find the group and trap with a door frame 3 fall trap with Ramps. Technically you just need to kill the 2 betas under the alpha and it'll be ready to tame. I tamed plenty with killing just 2. But to be safe kill them all. Use an argy and crossbows if it's early game with plenty of arrows and can be done without even being far into the game. I used prime meat. The taming bar goes down but they ask for food very fast.