Upgrading Power-On Button Wires

Is there any such thing as changing out the wires for the Power-on button and LEDS, Reset Switch and LED to bring the desktop case up to P4 standards or will I have to invest in a new tower case? It just seems to me that if I’m able to switch out the power supply, I should be able to switch other related items to bring the case or items up to the needed standards.
Many thanks for any ideas and answers whether good or bad?!