I'm doing a glue down engineered. I'm trying to avoid any unnecessary trim (no shoe molding etc), so I was hoping to go under this threshold after I rip out the tile, but doesn't appear to have much clearance.

Is replacing the threshold difficult? Any advice appreciated as always!

http://usera.imagecave.com/ronnald/door1.jpg

Don't even attempt to remove that threshold. It's probably screwed into the sides of the jambs. That is a prehung door unit and came in one piece to make the installation quick and easy. It's sitting on the subfloor or slab, whatever you have, so there won't be a way to go under it. If possible, just butt into the threshold. You can "net" cut engineered safely many times at doors. That's what I'd do. Or maybe fabricate a small reducer trim to sit on top and cover the gap.

Gary,
Thanks a million! I will butt the ends to it.

BTW, what do you mean "net cut"?

Thanks!

Net cut refers to cutting a piece of material so that it fits tight to another object.