Hi
Here is the style code used for the play button in the template
.ja-video-list .btn-play {
position: absolute;
background: rgba(0,0,0,0.2);
border: 2px solid #2637a6;
color: #ffffff;
left: 40px;
bottom: 40px;
border-radius: 50%;
cursor: pointer;
z-index: 2;
width: 40px;
height: 40px;
font-size: 10px;
line-height: 36px;
text-align: center;
}
You can override the code using custom.css file and then change the style values to move the button as you required.
I suggest you use Firebug or inspect element from the browser that will help you to test the style code in short time.
Regards