The side saddle uses bolts that go through the trigger group pin holes.
You simply push the pins out and run the bolts through the holes and tighten in place.
The only watch-outs are to be sure not to tighten the bolts too tight. If you really clamp the saddle down, it can squeeze the receiver together and cause feed problems.
The other watch-out is to be sure the saddle chosen will work with your fore end. Sporting fore ends are longer, and will bump into the saddle, preventing the gun from operating.
You will either need to buy a short side saddle, replace the fore end with a Police-type, or shorten the original.
For sling swivels, the method of installation depends on the swivels you want to use.
Some require not only drilling a hole, but also countersinking it. A special two-stepped drill/counter sink is sold for this.
Most quick-detach swivels need only a pilot hole in the butt.
Fore end swivels depend on whether you have a magazine extension. Swivels for extension mags usually attach to the bottom or side of the extension support bracket.
Swivels for standard guns attach to the hole in the magazine cap.
Most fore end swivels are attached with nothing more than a screwdriver.