I love this exercise!
Its easy and you can do it at home with no equipment but a plate or kettlebell.
Grab a light plate or kettlebell and get in a genie stance with your feet and knees together, then lean back with the weight, resist coming up and then repeat.
Make sure to keep your entire body in a straight line while leaning back.
Try 3-4 sets of 15 reps!
Feel the burn. Let me know how it works out for you!