There are two styles of rocker shafts for the 550, one shaft for each (8 total) and 1 Shaft for two (4 Total). The later has locking pins, the former doesn't.
Honda supplied the newer 4 shaft cover design on CB550K Engine # 1083641 and subsequent and CB550F Engine # 1133172 and Subsequent.
In both cases, the cam cover should be removed, the end caps/plugs removed and the shafts withdrawn from the cover to release the rockers.
Removing the cover releases the valve spring pressure on the rocker and shaft. If you have locking pins, then that also must release to extract the shafts.
Reassembly is where you can do real damage if you don't back all the adjusters out fully and unsure they don't catch on the valve stem when tightening down the cam cover. There is a specific warning in the shop manual about this. And, if unheeded, can resultsand many bent valves that are expensive to replace.
Cheers,
