In a lay led Liturgy don’t try to give a homily. The aim is to facilitate a sharing of reflections from the congregation. Perhaps two leaders could initiate the sharing. Official directives also indicate that there should not be a homily at a lay led Liturgy, but a reflection after the gospel commenting on the relationship between the Word and everyday life is encouraged.
Be clear that the sharing is not to be a doctrinal or scriptural explanation but a sharing of what the readings mean to the speaker, or the sharing of some experiences that illustrate the message in the proclaimed texts.
As one seeks to encourage the congregation to become comfortable with this kind of participation, perhaps children, with fewer inhibitions, might lead the way by commenting on questions put to them by the leaders in a non-threatening way.
When people reach the stage of being free to share their thoughts and convictions, their doubts and their questions, their worries and their joys, then the possibility of full participation in the Liturgy has really opened up. Obviously this can best be put into practice in congregations that are not too large.