Neither, no bolts required. The backrest has spring mounted forks. You slide the front forks around the front studs, then compress the backrest frame and slide over the rear studs. Done.
Correct - it goes over the hand hold bolt locations. A new one ships with plastic sheaths that you take the hand holds off and put the plastic on - to protect from paint scratches. The backrest works just fine without those installed (I bought mine used and didn't come with them). There is a nylon/fabric loop on both sides that clips on 2 little plastic tabs sticking up under the passenger seat. This is what keeps the backrest from just being stolen. To put on you pop the back seat, put the backrest on as mentioned above fold the fabric loops over the plastic tabs and put the seat back on. Super simple on and off. You don't have to take the backseat on/off if you don't care to use the extra "security" of the loops.
Another option is to add the topcase, as it includes a passenger backrest. If two up, you probably need the storage. I know it is a bit more, but for the money you are already spending, you are a third of the way to the topcase. This is my 2017 F3T that is almost a Limited now. Added foot boards, then the topcase. I prefer adjusting the rear shock airbag myself and don't need heated grips in TX.