First go to a safe place where you can be yourself, then meditate for a bit to clear the mind.
When you are completely relaxed, think of your animal. Imagine you are the animal, and doing things the animal would do. Let go of your human thoughts, DO NOT PANIC! Let your animal mind take over. Be the animal. When you feel the urge to move do not resist.
Be the animal for as long as you want, in this shift you will have the mindset of that animal. Do the things your animal wants to do. If this means howl, chase mice, or anything else, don't hesitate!
When you wish to shift back it is quite easy. Your human thoughts will always be in your subconscious. Pull your human thoughts forward, and Walah! Start thinking like a human again.
I hope you enjoy!
Feel free to message me your experience!