This is a step-by-step tutorial I wrote up to help new Xangan's with installing a HTML layout from Lumos Maxima. I tried to write it as straight-forward as possible. If you are still having trouble, you are welcome to comment/e-mail me for further assistance.
1. First, you need to decide on a layout. [A list of all available layouts can be found here]
2. Once you've picked one, scroll to the newest post on the live example site [i.e: www.xanga.com/E_Layout1. The number on the end will change] for a textbox containing a lot of text. It will look something like this:
3. Highlight and copy only what is located within this box. This is the HTML code needed to define the look of the layout.
4. Next, while signed into your private site, go to your Look & Feel. [as a new security feature, it will ask you to sign in again]
5. What you need to focus on is the Header section. As a default, it is set to 'Hide Header'.

6. Since you have a custom code, you need to change that. From the drop-down list, click on 'Input your own Header HTML'.

7. Now a large box opens below labelled 'Module:'. This is where you need to put that code you copied.

8. Right-click in the box and click paste. Here is where you need to pay attention to what kind of code it is. Most codes require no editing to the final code, however a few of my layouts have custom modules, so you need to input your own information. Go through the code, and wherever you see links with the word 'USERNAME' - replace that with your own Xanga username. With any custom modules, just fill in whatever icons/pictures/info you like.
9. And you're done! Click the 'Save Changes' button at the bottom of the Look & Feel page and head back to your site. Your new layout will be there. Enjoy! :).
____________________________________________________