You can use FCPX, as well as several others, to convert VHS source to HD format. You are not going to make the video sharper or look better unless you know what you are doing. And then only marginally better with FCPX. Typically the colors are off and there is a bit of noise that those pro shops that make their living converting VHS to DVD know the magic (and have the video processing equipment) to correct and make them look quite a bit better (not HD but looking more like modern video). What I've been reading over the past few years it that the equipment and software needed to make significant improvements in VHS video quality is not cheap and there is a steep learning curve. Its been less money and you will get better results by sending the video to a pro shop.