Remove handle related parts from the reel. Then remove the star wheel. Next, remove the right sideplate and the brakeplate from the frame.
Separate the sideplate from the brakeplate by unscrewing the two brakeplate screws. Remove wire-clip #10259 and the existing plastic bushing #10226 along with supporting spring #10245 underneath.
Drop the replacing spring with the larger diameter into the housing. Then place the custom plastic bushing in the upright position over the spring. Make sure the longer side of the bushing is looking downward just like in the picture. Place the #10259 wire back in position over the plastic bushing.
Next, replace the spring #10228. It is simply placed in the tight area of the clutch button but it is just snagged in there and not been tightened or screwed down. I would recommend using a very small screw driver for removing.
Fishy Business, Inc.
Result may differ from the reel to reel subject to its current condition. Sometime the reel may have some other issues that may have contributed to the heavy clutch issue.