'98 Prelude Transmission Questions

A few years back I made the mistake of buying a '98 Prelude with the automatic transmission instead of the manual. Now at 85,000, my transmission is completely shot and I need a replacement. My question is, how hard/expensive would it be to switch out a manual in the place of the busted automatic? Would it be worth the time or should I just go with a replacement/rebuilt automatic transmission with a 2 year warranty? I have some friends that have switched out the automatics in their Nissan 240's, but I have a feeling that it might be a little easier and cheaper than it would a Prelude. All help is greatly appreciated.