Things You'll Need
Instructions
Getting around Enabling WMA Playback on a PSP
Connect to the Internet and download Switch Audio Converter Software from NCH Software for free here: http://www.nch.com.au/switch/
Install and run the Switch Audio Converter, finding all your WMA files on your computer that you want on your PSP and converting them to MP3 format.
Connect your PSP to your computer via a PSP-compatible USB cable.
On your PSP, browse to the folder "PSP" and then to the folder "Music" (if the folder doesn't exist, create one).
Drag and drop the MP3 files you just created into the music folder on the PSP.
Eject the PSP and disconnect it from the computer. You should be able to see and play your MP3 files in the music section on the PSP.
There are download links for Windows PCs, Power PC Macs, and Intel Macs.