You will need a dedicated tool to open and modify RPF archives. The two most common and widely used tools are:
Because this file is essential for the main character, altering it improperly will cause the game to crash, particularly during cutscenes, as the game engine attempts to load the broken model. Why You Need a playerped.rpf Backup gta+4+playerpedrpf+backup+upd
For more complex modding, you may need additional tools: You will need a dedicated tool to open