The suggestion given to you by downunderdog is the right one. If it leans to either side(leaning is called yaw) you should correct this problem by disconnecting and shortening or lengthening(this depends on what direction the leaning occurs) the servo linkage rods.Centre all trims and connect a battery pack,work your way from there until the swashplate is level adjusting the servo linkage rods if the tx trims dont totally correct the yaw. Dont worry about the heli being difficult to fly,with the right trim and some patience you will soon become a pilot. Took me a week of blade breaking to feel i could fly (almost) anywhere.