ISO to big

Hey iv'e recently started using a HEN on my PSP 3000, I looked at a download of Metal Gear Peace Walker but the iso is to big :'( is there anyway to split it into multiple parts? I have also looked at GOW ghost of Sparta and that was in multiple parts.
So how do i split it up and play each part seperatlyThanks in advance

No, you can't.However, you can compress it to .CSO using either UMDGen or PSP ISO Compressor.