I bought all the needed parts from Brownells: safety screw, detent, detent ball, mil-spec safety, et al.

Now, can anyone walk me through the installation?  

Remove the barrel by loosening the thumbscrew at the end of the magazine tube.  Remove the bolt.  Push the trigger housing retaining pins out and lift the trigger group out of the receiver.  Remove the screw in the middle of the safety button and take off the safety, detent ball, and spring.  Hold the safety by reaching inside the receiver when you remove the button.  When you put her back together, the protrusion on the safety needs to face the rear of the receiver.

-hanko

Thanks!