Disfellowshipping does not have to be done away with. Shunning has to be done away with.
A disfellowshipped person should simply have his status as one of Jehovah's Witnesses revoked, returning him to being just another member of the public lacking all the privileges in the congregation that only baptized and unbaptized publishers are permitted to have. Additionally a disfellowshipped person should also be treated as a marked individual who is on reproof.
Where I am, a JW on reproof cannot comment at the meetings and is associated with less, by some JWs. But he is not shunned. I think that is how a disfellowshipped person should be treated.
But beyond that I think the whole criteria for disfellowshipping needs to be revised. The whole idea of elders trying to discern the repentance of an individual based on his words and body language is foolish. A person who commits a serious sin once and isn't continuing in it should not be disfellowshipped, period.
Disfellowshipping should be reserved only for those who persist in the serious sins that 1 Corinthians 5 mentions.
A JW who commits pedophilia should have a lifetime ban on having any authority in the congregation - even if he is reinstated as a JW - and all in the congregation should be informed of his status as a sex offender.