The Side Saddle is pretty easy to install. It comes with two screws to replace the ejector screw and the pin that holds the trigger assembly in the receiver. If you know how to use a screw-driver and an allen wrench, you can do it.
(the allen wrenches are included with the Side Saddle, BTW)
I agree with Dave about the sling. I have one for range use, but I don't recommend it for home defense.