Get to grips (with) (7)
(Other definitions for wrestle that I've seen before include "Struggle, grapple" , "Fight in the ring" , "Tussle" , "Grapple on canvas" , "Struggle physically or mentally" .)
(Other definitions for grapple that I've seen before include "struggle" , "Attempt to get hold of, or seize" , "Go to work on" , "Engage in close fighting" , "Lay hold of" .)