I have a pair of French doors with 2 fixed side panels, the cill is completely rotten with a small bit of rot on a couple of uprights where jointed into cill. I was considering cutting these out and replacing in situ rather than taking the whole frame out, but it seems a bit tricky re aligning and jointing the cill with the frame in place. Is this the best/worst way? Is this what the experts do? I've done a fair bit of joinery so I'm ok with the jointing etc. Anyone with experience of this? Any suggestions will be very gratefully received.
John