Honda BF35A-BF45A Outboard Motors Shop Manual., Page 408Get this manual
6) Remove the spool valve cap using commercially available 2.8 mm driver bit DRIVER BIT, 2.8 mm lavailable) l
Apply small squirt of air pressure to the oil hole in the spool valve cap to remove the valve BRemove the valve from the spool valve capRemove the O-rings from the spool valve cap and valve and discard themReplace the O-rings with the new ones during reassembly