Honda BF15D BF20D Outboard Motors Shop Manual., Page 217Get this manual
5SWIVEL CASE aDISASSEMBLY
1) Raise up the tilt arm and unhook the tilt link spring from the hook on the swivel case then remove the tilt link spring
2) Stretch the bent tabs of the lock washer and loosen the 6
mm hexnutRemove the mm hex nut and lock washer, then push the tilt arm shaft slightlyReplace the lock washer with new one when reassembly