That is what I was suspecting from reading about this.
Is there any guides on changing these?
first need to check the basics, ie oil pressure and compression on it as no point repairing the top end on a engine with oil pressure as would need to do the whole motor which will be a lot of money engine out job, the valve stem seals are common and will need a valve compression tool and a magnet and vaseline jelly ie makes it easier to get collets back on the valve stems ends to lock the spring,, also need a timing chain locking kit, torque wrench, and i use tipex to mark things like head bolts and cam shaft bolts to know at what stages i'm at when doing them up as head bolts have 3 stages.
also will need sockets 1/4 drive set with extensions etc is very handy for the nuts on the exhaust manifold as these can be a battle as need to remove the studs if not removing the cat, and will also need a torx set on sockets and bits,
links below worth a look at i know its on a n14 both heads are same thing except your non turbo one will have twin vanos and is not direct injection, but all the rest of the job is the same,