Now that you’ve got a plan, it’s time to head to Whiterun and see about getting things set up to trap a dragon. Depending on what else you’ve done during the game, this can be simplicity itself, or it can require an extra trip.
Most players will not be done dealing with the war between Imperial forces and the Stormcloaks. If the war is not concluded (or at least nearly so), then your conversation with the Jarl of Whiterun will be similarly inconclusive. Should Jarl Balgruuf the Greater still be in power in Whiterun, he will point out that both sides of the war are just looking for him to show some weakness so they can send forces in to take over- and he therefore cannot possibly allow you to spend some of his troops protecting the city from a dragon and leaving Whiterun weakened. You will need to propose to him that you can draw a temporary truce between the two sides, at which point he agrees, conditional to your succeeding in calling this truce.
If the war is not over and Jarl Vignar the Revered is in power in Whiterun, he will point out that the Imperial forces badly want Whiterun back and, as Jarl Balgruuf would, he will refuse on the grounds that it will leave his city vulnerable. Again, you will have to propose to him that you can call a truce between the two sides that will keep Whiterun relatively safe.
If either of these is the case, please move on to Part 16b, and read from there.
If one side or the other has completely won Skyrim’s civil war already, or if the losing side has only one hold remaining to their name, then the Jarl- Balgruuf if the Imperials are winning, Vignar if the Stormcloaks are winning- will qualify that your idea is completely insane, but still be willing to go along with it. The Jarl is reluctant, though, and bids you make your attempt to snare a dragon as carefully as possible- he does not want any more threat to his city and citizens than is absolutely necessary. As this is a reasonable request from the man responsible for Whiterun’s safety, you should agree in some manner- at which point you can head out to the Dragonsreach balcony, which is already prepared for this. I will leave it to your own imagination how it is that the Jarl’s men got the place ready in the time it took for you to conclude the conversation- that’s not really the point. The point is, it’s time to trap a dragon. Please move on to Part 17 of the walkthrough.