By the way, reinstalling the bolt is a challenge to the uninitiated.
Here, you have to hold the trigger rearward throughout the process. Once the bolt is started into the receiver, it will only travel a short distance before it contacts the sear and stops. With significant pressure, you can force the bolt over the sear, but I prefer not to do that, not knowing the long term effects on the mating surfaces. The trick is to maintain mild forward pressure on the bolt with one hand while holding the trigger rearward with the same hand (I use my thumb on the trigger, but you'll figure it out). Meanwhile, reach into the action behind the mag well with a small non-marring tool (dowel, pencil, or your baby finger if it's slender enough) and depress the sear downward, allowing the bolt to pass over it. If the bolt then moves only a fraction of an inch forward before stopping again, it's because the lower lug on the bolt is not quite aligned with its raceway on the back of the receiver. Just rotate the bolt a bit until it enters. If you look at the back of the receiver, you can see this misalignment real-time. Don't force this, as it will mar the receiver.
This is all quite simple once you do it a few times, and only takes a few seconds each way. But after any significant down-time, I can seldom recall it all, so I keep a printed copy in my range log-book.
