Easiest Approach for Making Hole for Split AC Installation in Wall
Details about Rotary Hammer drills are already mentioned in this link;
Once you have rotray hammer drill with you, you simply need to buy 2.5 inch dia chuck along with supporting shank bit. YOu easily can make 2.5 inch holes in wall without damaging wall or any manual hard work.
By this method, you walls will be safe from hammering impacts and cracks development due to conventional method.