Bernie Hunt wrote:
I removed the carpet from our stairs and there are two treads that are
split. I don't have access to the bottom due to a plaster ceiling
underneath. The treads are high on the flight so both ends of the tread are
encapsulated in a dado in the stringer. I'd like to remove and replace the
treads.

Getting the old tread out will be messy but quite possible. I figure to
plunge cut into the middle with either a circular saw or a Fien with the
right blade. My question is how to get the new tread installed?

Any suggestions? I have a full woodworking shop, so very little is not
possible. I've just never worked on a stair case with both sides
encapsulated into the stringers before.

Here is a picture of the left and right sides of the stair tread.
http://www.cybertecservices.com/files/imag0110.jpg
http://www.cybertecservices.com/files/imag0111.jpg

Thanks,
Bernie

I'd go with the drill, glue, and screw as others mentioned. If you want
to clamp it before installing the screw (I would), wedge a 2x4 between
the edge of the tread and the wall opposite (cut to length). If the
opposite wall is sheet rock or plaster, first use a 2x4 across 2 studs
so it doesn't poke a hole in the wall.