Step 1. - Download the code generator. - CLICK HERE TO DOWNLOAD
Step 2. - Generate a code, copy it, write it down, VERY IMPORTANT!
Step 3. - Log in to PSN and go to the "Redeem Code" Page. It is the same page to redeem a giftcard.
The points should be credited to your account instantly. Sometimes you have to try more than one code to get an unused one. The program generates a code, and when you redeem it they think you are just redeeming a giftcard.