1. Make sure your MAC is unloaded.
2. Open your new UZI style folding stock by pushing against spring pressure and unfolding.
3. Remove your old stock from your MAC.
4. Remove front pin securing upper and lower receivers.
5. Remove the upper receiver.
6. Inside the rear of the lower receiver, push down slightly and to one side on the pin securing the push lock for the old stock.
7. Remove all old parts.
8. Insert the lock bar provided with your new folding stock. Holding the lock bar in place with your finger, turn the receiver over and thread the bolt (provided) in a few threads by hand.
9. Insert the stock fully into the lower receiver and lock into place with 5/32 (4mm) hex wrench.
10. Reinstall upper receiver and pin assemblies.
11. Tighten bolt just enough to hold stock in place without moving.

DO NOT OVERTIGHTEN!