In order to install these freebie layouts all you need to do is follow these steps:
1. Log on to your blog and click on "Customize"
2. Click "Pick a New Template" under the "Layout" tab
3. Select the first one, the "Minima" template
4. Click "Page Elements" section under the "Layout" tab
5. Click on "Add a Gadget" at the bottom where the footer is.
7. Copy the code from here of the background you like and paste it in. Click "Save"
You can then tweak "Fonts and Colors" under the "Layout" tab to match your new background.
Christmas Time Is Here
These are a bit different. They require you to download the code and then insert it into your "edit html" box.
This freebie is called "Fall Leaf Shower". Click HERE or on the image for a larger view.