Warning: By no means am I professional graphic artist or a teacher.
We're getting fancy. I might move too fast so ask any questions in the comments. The goal is to do the same cover just with a gradient.
First thing first? SAVE AS. Come on, you had to know that was coming. Since I don't want to redo all the font work, I'm pulling it down below the White Background Layer. That involves clicking on the various layers and dragging them down.
Next: New Layer. Right click either the image or a particular layer in your Layers-Gradients list, you get a menu. Pick New Layer. I cannot stress New Layer enough or even duplicate layer. If you're going to start changing things, don't do it to the original.
Once you click New Layer, a menu pops up. You want the last option: Transparency. It's going to look like nothing is added until you look at the Layers-Gradient list. There's just a blank layer waiting for ya.
Now to blend.
I'm going to choose the blending tool. It's highlighted in blue in the Tool Box.
The options I chose, you can see those on the right, are FB to Transparent. I'm leaving the Opacity at 100 percent.
(If you don't know the names I'm using, enlarge the pic and find it. )
I want the bottom half blended to better bring out that whatever font I use in that area.
That line you see is the direction the blending tool is going to go. If I wanted to start in the corners, then I'd hold down the left mouse button, hold until I got to the part of the cover that would have the most faded part of the gradient.
So, I did the gradient tool twice so it was really dark by their legs.
Boom. I'm done. Let's put back my name and title.