Place zucchini in colander over bowl. Sprinkle zucchini with salt; let stand 30 min. to drain. Wrap zucchini in clean kitchen towel; use to squeeze remaining liquid from zucchini. Place zucchini in medium bowl.
Heat oven to 400°F. Brown meat; drain. Add to zucchini along with the cheese, eggs, milk and bread crumbs; mix well.
Place 1 phyllo sheet on clean work surface; brush lightly with some of the butter. Cover with second phyllo sheet; brush with butter. Place double layers of phyllo dough in 9-inch round pan sprayed with cooking spray, letting ends of dough extend over side of pan. Repeat with 6 of the remaining phyllo sheets, crisscrossing double layers of dough as necessary to completely cover bottom of pan.
Spread zucchini mixture onto bottom of crust; cover with remaining phyllo sheets. Fold ends of phyllo dough over top of pie; brush with remaining butter.
Bake 45 min. or until golden brown. Cool in pan 10 min. Unmold onto serving plate; cut into wedges to serve.