Car remote programming help?

I have a 1999 Chevy Astro Van and bought a replacement care remote. The specifications are; DEI (Brand) RPN471T and the FCC ID:EZSDEI471. I bought the replacement remote but never got around to programming it because my original one was still in working condition. My original is now pretty beat up and I would like to program my new one. The thing is, I lost the programming instructions and cant seem to find them. If anyone could please help me out with the programming instructions, I would greatly appreciate it.