Ordered correct replacement parts (your online form helped to identify correct valves 2 had black dot on inside stem for back small burner 1 had red dot for larger front burner). locked stove, turned off gas, unplugged cord. removed knobs, 5 screws and front plate also removed L shaped plate below knobs for better access to comp. fittings. pulled off ignitior controls loosened compression fittings (hard to get wrench on nut but doable), removed screw holding valve to manifold. reversed order for new valves. Lit burners and sprayed soap solution on all joints to check for leaks. All good.