Once you have the highly compressed .cso file, follow these steps:

Always check:

The emulation community has done something magical. Using , they have converted the PS2 version of Shaolin Monks into a format that the PPSSPP emulator can read. This "unofficial port" is then shrunk down via CSO compression (sometimes from 3GB to under 300MB), creating the "Highly Compressed" version you see across forums and YouTube videos.