The ratchets will have to be individually cut to accomodate the width of the hand so that the hand will be able to pass them, and enable to cylinder to carry up properly. This is done with a Nicholson 4", 0 cut barrette file. The hand is not modified.
If you don't have experience cutting ratchets, this job is better left to a trusted, experienced gunsmith, or contact S&W.

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Ret. LE, FA Instr, S&W Armorer