sleek, I have taken the sinew off,, then re applied a new sinew backing, with positive results,,
I have not tried putting back on the old sinew backing,, I think that would be more difficult than making a new one,,
but since I have not tried it,, could be wrong bout that,
I think soaking it off would be your best bet,, as far as putting it back on,, if you put it on stiff might not work too well,,,, maybe just get it a bit damp so it would conform to the shape of the bow,, I am guessing now so take that with a grain of salt,,