changing html to php

[ponygirl]

I didn't know where to put this but I figured someone in here could help me

I can't believe I didn't think of this before I started all this work but I'm looking at changing just my index/main pages on my LL from html to php and wondered if anyone has done this & what they did about their link trades? I also have recips pointing to main.html, so what would be the best way to redirect that to the .php?

thanks for any input!