Complex sentence: A slight reform of the liturgy was effective since 6 January 2007, and it aimed to unify the many different uses of each parish, to remove centuries-old additions that merely imitated the Roman Rite, and for pastoral reasons.
Split into simpler sentences: A slight reform of the liturgy was effective since 6 January 2007. The aims are to uniform the many different uses of each parish, to clean up the things added in the centuries simply to imitate the Roman rite, and for pastoral reasons.