That's a frustrating issue! What tournament/state is this? Maybe someone here is available to swap, but you'll likely get a good resolution by contacting the tournament director directly. Here are some possible solutions that you can suggest to the tournament director if he or she doesn't suggest them to you:
1) Ideally, the tournament director can ask the teams signed up for the 2 PM hour if they can swap. The swap might be a direct 9 AM to 2 PM swap but it might be a three- or four-way swap.
2) Ask the ES if you can squeeze in at 2 PM, running as soon as the other teams finish, even if it means running past 3 PM.
3) Ask the ES if you can run at 8:30. If this is a Regional tournament, then there's no impound. But, if it's a state level tournament, an early run will have to be hidden from those impounding (different room, divider between impound and run area).
4) Much less than ideal, if either student is available at 9 AM but the other one isn't, perhaps that available student can run then with another team member with the understanding that the busy partner will receive any medal earned since he or she has worked hard on the event. This is tough because the sub would have to know when to touch, what to look for, and how to answer ES questions.
Best to you