1) You need the TXDWorkshop tool or any tool that can open .txd files
2) Open particle.txd with TXDWorkshop (located in your gta san andreas/models folder)
3) Find and replace "coronastar" with this "coronastar" from "Textures for the 2dfx lights" folder

*This is only if you have another modified particle.txd file and you want to install these textures manually*