So, the steps would be:
1) Select one carrot and press Q (while crouched)
2) Throw a carrot towards the bunny
3) Once the bunny begins to eat the carrot on the ground, quickly go in front of her and hold Q (while crouched)
4) Once the bunny diamond turns Pink (before bunny comes at you), stop holding Q and quickly move to your nearest taming spot (the green totem things, which light up on approach. You should've seen it in story, when Black tamer teaches you how to tame. Look around the area to find them)
5) repeat step 3 and let the bunny grab you
You can recheck the taming in Book popup (tab , then E button, then left-right-up-down to navigate)