Most places will want the head striped- cams off, tappets out, and valves and springs off. The cams come off by undoing the 2 m8 nuts on each cap, think theres 6/7. The tappets just pull out, but number them so they go back correctly. And the valves will need a spring compressor tool, and same as above, pair and number the valves and tappets up. When you rebuild the head, you will need to lap the valves back into each valve seat. And use new valve stem oil seals. When the tappets/cams go back in, use plenty of oil in oil ways and metal to metal surfaces.