perl -CSD -Mutf8 -pe"s/’/'/g;"

##</code><code>##

$ echo It’s easy | perl -pe"s/’/'/g;"
It's easy

##</code><code>##

$ perl -Cio -pe"s/’/'/g;" <( echo "It’s easy" )
Wide character in print at -e line 1, <> line 1.
It’s easy

##</code><code>##

$ perl -CiO -Mutf8 -pe"s/’/'/g;" <( echo "It’s easy" )
It's easy

##</code><code>##

$ echo "It’s easy" | perl -CIO -Mutf8 -pe"s/’/'/g;"
It's easy

##</code><code>##

perl -CiIO -Mutf8 -pe"s/’/'/g;"

##</code><code>##

perl -CSD -Mutf8 -pe"s/’/'/g;"