for the words " paragraph (b) of the said subsection " there shall be substituted the words " such of the crofters referred to in paragraph (b) of that subsection as are liable to pay any expenses in accordance with a proposed allocation of expenditure referred to in subsection (1A) of section 25 of that Act or, as the case may be, such a proposed allocation as approved or modified by the (Commission under that subsection ";

for the words from " discharge " to the end there shall be substituted the words " performance of the duties imposed on them by paragraphs (a) and (b) respectively of section 25(1) of that Act. ";