If you want to play a game with the updated kits, you should check you have the capability to do this first.
1. You will need a chipped/modded PS2,
2. be able to download the (possibly large, maybe 100MB) patch,
3. Rip the PES3 onto CD (or not if you have DVD-writer) and
4. be able to burn it onto a CD-R or DVD-R
There is no easy way to get the updated kits to work either on your original copy of PES3, with an update disk or an X-Port so make sure you can do all of the above.