How do you replace the heater core in a 87 Honda Prelude?

I'm pretty sure you would have to remove the dash unless it's accessible below the passenger side of the dash. Root around there for anything. If it's leaking in the cabin you can locate it easily....

I replaced the heater core on my 1987 Honda Prelude Si last year. The air conditioning evaporator box will not allow you to get to the heater core without removing the entire dashboard. First you have to remove the instrument panel, and then remove the rest of the dashboard to get to the heater core. I bought a 87 Prelude shop manual on eBay and that really helped in showing me where all the bolts and screws are located that hold the dashboard. I had 1 screw left over...but the car and heater core work great!