I'm going to try to be as simple as possible here but if you still don't get it then feel free to message me.
What you want to do is go to layouts.spacehey.com and find a layout that you like the look of. Once you find one, click on it and there should be a section titled "Code:". Below that is a box with a bunch of html stuff. You want to select everything in the box. (To make it easier just click in the box and do Ctrl+A and then Ctrl+C) After you have everything selected and copied, head to your profile and below "About Me:" there should be an edit button. Click on that and below all that text you have in your about me you just paste the code you copied (Ctrl+V) and save.