Self amending treaty
The Lisbon Treaty contains 68 new areas for decisions by qualified majority votes. The Prime Ministers are permitted to change remaining areas with unanimity to votes by qualified majority or use a special procedure to the ordinary legislative procedure.
Such decisions require unanimity - but no positive approval by national parliaments or referendums. That is why the treaty is called self amending.
The Lisbon Treaty also contains a procedure for simple revision by Prime ministers agreeing unanimously. Such changes shall normally be approved by national parliaments by ratification according to Art. 48.6 TEU.
See the Lisbon Treaty Art. 48.7 TEU for simple revision without ratification.
See also Ratification