The package, which goes to the vote at a special conference on March 1, will change the party's links with the unions and allow people to have a say in Labour's leadership contests without being full party members.
It follows last year's row over the party's choice of candidate in Falkirk. Mr Miliband became involved in a row with Unite amid allegations the union had tried to influence selection.
Mr Miliband says in an interview today the "seismic changes" were an attempt to increase public involvement at a time of declining political party membership.
Clause IV of the constitution committed the party to nationalisation, but Mr Miliband insisted scrapping it had been symbolic, and "this is bigger than Clause IV in its impact on the way it will change politics".
He also criticised former Labour prime ministers Mr Blair and Gordon Brown by saying: "We would have been a better government if we had been listening to people on the ground."