Easy straight swap! Undo bolts, undo lambda sensors, take decat off! Fit sports cat bolt it in place put lambda sensor back in place according to order they were taken off the decat and your done! Should b easy as long as bolts on fixing flange arnt seized!
Never done this myseld but the garage who fitted my sports cat said the fiddly bit is putting the bolts back on, quite a tight squeeze for you hand