Helping customize a theme, please help! :)

[Magestickown]

Firstly: Why doesn't anyone respond to my threads? D: Threads that are posted seconds after mine are answered first, like I'm third priority or something.. ANYWAYS;

Using the theme "Brkdmrcn" I want to customize it a bit more to look similar to my website. I change the background to the same, but I want to add the top part of the background, which is a gradient of the background.

How can I do this?..
Here's what I mean:

http://www.dcfilms.ulmb.com/

http://www.dcfilms.ulmb.com/dc/forum

Here's a blueprint of what I mean:

Forum:
XXgradientbackgroundgradientbackgroundgradientbackgroundgradientbackgroundXX
XXmenuandbannermenuandbannermenuandbannermenuandbannermenuandbannXX
XXboardsboardsboardsboardsboardsboardsboardsboardsboardsboardsboardsboaXX
XXotherstuffotherstuffotherstuffotherstuffotherstuffotherstuffotherstuffotherstuffotXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

X = Background




Thanks in advance!