Removal of cylinder heads

The cylinder heads, and the barrels, are held on by long studs from the block. There are eight nuts holding them.They should be loosened and undone in the same sequence as for tightening. Some of the studs will undo from the block and others will not. After removing all of the nuts we removed all the studs by using the 'double nut trick'.
I think the stud removal helps when removing the barrels.
The heads come off first and then remove the barrels. There is a plate under the barrels that clips off. The two barrels on each side are separate units.
The stud bolts hold the heads and the barrels and the pushrod tubes are clamped between the heads and the crankcase. Some tubes come away with the heads and and some stay in the crankcase.
The guide warns against turning the engine at this stage to prevent any damage.
The barrels were quite tight and the guide says tap lightly with a soft faced hammer. We used a block of wood and a hammer but did, unfortunately, damage one of the fins.
I don't think this is a disaster but should be avoided if possible.