my driver side door handle has broken I went to put my key in entry and the ent on 1999 Cadillac Escalade

the key entry to my door has pushed back when i put my key in the the whole lock is inside the door somewhere I imagine. What do I do and what's the ball park price on having it fixed?

Asked by for the 1999 Cadillac Escalade
remove door panel the retainer clip fell off. very simple fix appox 90.00 to repair