Under, as down the middle of the room ? Or would this be run along the baseboard ?
Baseboard is easy.. Just use a putty knife, and push the wire down into the gap between tack strip and wall, just under the baseboard.. Same procedure they use to lay the carpet.. Nothing needs to be removed, replaced, etc..
Under the carpet would depend on the subfloor material.. You lucky enough to have a basement, or crawl space, or is a cement slab ?

LFE ! The rest is just details..