There have been many movements toward a renewal of the liturgy in these last few months and years. Perhaps the most noteworthy project right now is the movement for a free collection of propers for the Mass. Nevertheless, even once this project is finished, it must have support of pastors in order to be implemented in parishes. How might ordinary laity engage in renewing and reforming the liturgical practice in their own parishes?
The primary answer is to stake out that ground which is currently not held or even contested by anyone in the parish. We know that Sacrosanctum Concilium called for Sunday Vespers to be celebrated in common in parishes. Individual Catholic laity may certainly join in praying the Hours together, with or without clergy (though clergy are to take their appropriate roles when they are present). The Catholic laity are certainly not forbidden to gather together as a community to pray. If they meet for a sung Vespers, learn how to chant the psalms, etc., they have undertaken a vital step in renewing the liturgical life of their parish.
Moreover, they have something which they can bring to their pastor, inviting him to join with them. I can't imagine many priests saying "no." They may then ask for the permission to use the parish church when no other event is scheduled in the evening. Again, I can't imagine a priest here saying, "no." Finally, they can invite him to take his own proper role in leading the prayers of the people (as well as any associate pastors or deacons). While some priests may not opt for this option, it's probably safe to say that many will.
This may lead to further opportunities for renewing the liturgical life of the parish. Think, for instance, of all those daily Low Masses in almost every parish in the country. Even Solemnities receive this treatment, so long as they are not also Holy Days of Obligation. If a group is able to sing the simple chants of the Mundelein Psalter, they are probably able to sing the chants of By Flowing Waters, which sets the texts of the Simple Gradual. You might then be able to provide the chants from the Psalter for the Entrance, Offertory, and Communion. While there might be some opposition to such an offer before starting a Sunday Vespers, once competence is shown, it's easy to imagine such opposition subsiding.
We have many opportunities out there. We should seize them. Don't just fight to change the way things are. We can work together to improve things as they now stand, and start things that aren't yet being done.