First of all, start removing the head engine case cover bolts (13mm). You’ll have two long ones on one side, and two shorter ones on the other side – make sure you remember which goes where! Once those bolts are out we can remove the cover and then we need to remove the decomp valve cable – use a 10 mm spanner and loosen the holding nut on the rear side. This will give you enough room to unthread the wire from the other end and pop it out from the arm. Then we can remove the bracket from the other side from the head, but put the bolts back into the head.
Then we can start undoing all of the other bolts (10mm open-end spanner, not a ring spanner, and a couple of 12mm sockets) on the head case. Crack each of them free, undo them by hand, then once they are free, place them back into the hole – this is because they are different sizes and we want to keep track of where each one is. Make sure you check your gaskets and keep them clean when you are removing parts. If your head case has never been removed, it’s likely going to be hard to remove. In this case, get a rubber mallet and tap it all the way around. Then slowly work it off, trying to keep the bolts in place. If you are leaving it for any amount of time, place the head case back on, then come back to it.