Ok, so for those of you making themes here is this tutorial for you.

Let's begin.

Tools:
1. Reboot/Shutdown Plugin
2. PSP capable of flashing.

Ok, now that wee got our tools, do the following.

Go into Recovery Menu/Mode and toggle flash0 and connect your
PSP to the PC via a USB cable.

So once your PC reads your PSP you will get something like this:


Click the option that's highlighted.
You will get something similar to this:


Ok, now that wee got the PSP connected, let's go to the installer.
The icon of it should be this:


If you DO get this screen, just click RUN.

Next, you will get this:


otice where it says, Destination Folder it has the letter X://
Change X to where your PSP is at.
For example, mine is K. So I'll change it to K:


Now, press INSTALL.


It shouldn't take long.

When it's done, just disconnect your PSP from the PC.
And restart your PSP.

Go, to the Network Update icon and press X to restart or R+X to shutdown.