There are 3 main ways.
1. Download the max drive version and use a max drive to transfer it to your memory card.
2. Download the x-port verson and use an x-port to transfer it to your memory card.
3. Download the bin+cue version and burn it to CDR and transfer using the CD2mem method. This only works on a chipped or modded PS2.
I think the easiest method is to buy a Max Drive from
here.