You can't do it!
80 min CD-Rs hold 700MB of data - a DVD 4.3GB (I think). It's a case of the old you can't get a quart into a pint pot, I'm afraid.
You would have to convert the DVD to a format that will fit onto a CD, main choices being VCD, SVCD, XVCD and DivX - all take a long time and a lot of processing and you will lose quality and features, unless you convert it to multiple files spread across a number of CD-Rs - to play on a DVD player you would need to use VCD or SVCD if your player supports them.
click here for help on tools, instructions and format compatibility with DVD players.