Halyard to sail attachment with Finish Line

[Firebrick43]

Hello all,

Please forgive my ignorance here as I am new to the High tech lines!

I have experience with three strand splicing and whipping and such but still lack much.

What I am trying to do is make an easy to undue attachment on my new to me 15' mutineers halyard. I listened to an aqaintance a puchased some New England rope finish line with the idea of spliceing an eye to it and using a soft shackle to attach to the sail. Well I went to NE ropes website and low and behold it nonsplicable!

Read some where about putting a stopper knot on the end of the line an then whipping and seizing a small loop of slightly smaller rope to the halyard to act as a shackle and this apeals to me except worry about stuctually the whipping and seizing of a structural part to a rope like this, I have not done. Is this even recommended? If so can some one recommend where to view instuctions for this kind of whipping?

Other hardware less and easy to unbent ideas welcome. Hard to untie knots can't be used as a 70 year old neighbor uses or sails with me and doesn't have the finger strength
Thank you
Jay