Hi Gazh, Just make sure that the soil is well firmed and for a small area like that, I lay the turf, then flood the grass then using a short plank, slam the plank on the wet ground and the new turf will be level with the old.
If possible, try to get the turf from the same lawn, maybe from around the edge, even if it means reseeding the area you took the turf from, that way its sure to match. It really depends wich piece is visually more important. Finally, if your taking up turf to do the repair, make sure you water it well before lifting, this will make your job much easier, and dont forget, water water water !
Lannerman