bet everyone's getting sick of me by now! still trying to solve my overheating prob and when i was taking pics of my t-stat housing(see other thread) i noticed another leak!

the leak looks like its coming from the top bolt(see pic) and coolant is leaking cos of the rust and bluish residue. the seal between the engine and this plastic housing(labelled in pic, not sure what its called)looks like its deteriorated too so i should replace this housing really. easy job or professional required?

does anyone know what that housing is called?




close up: