I have never removed one. I would expect it will take a lot of force to get it apart.
You might want to try your question on
http://forums.iboats.com/search.phpI would guess that you could make something like that OMC tool if you bought a large gear puller, and were willing to cut and weld pieces to it to grip the arm.
Sounds like it might be worth having a local marina do that part of the job.
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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings