To start, you must have saved your chosen background to your computer. Did you?  If you did, skip the rest and begin the numbered list below.  If you did not save it, this is how:  You must view your image on the screen. Then right click the mouse so that a little menu pops up. Select 'save image as' and it will direct you to save it on your computer. Remember where you saved it and begin the steps below.

1. Login to your Twitter account.

2. Click on the “Settings” tab.  Should be top right.

3. Select the “Design” tab.  

4. Click “Change background image” located below the Twitter themes.

5. Next, click the “Browse” button to upload the background saved to your computer..

6. Select your background from your computer, then click “Open”.

7. Click save changes. Page will reload with your new design.

Now, check you design colours and adjust to match your background.  

Dont forget to tweet your friends! Tell 'em how you became a twitter nerd because of Tweetcustom.com  Have fun!