How to catch a stray bun?

My house backs onto a primary school and we've noticed an obviously domestic bun on the field in the evenings. I'm assuming it's a stray and not just someone who backs onto the school and lets it roam free.
The school has an eight foot high wire fence surrounding it and the matching gates are locked after the school shuts. I'm guessing my first port of call is to email the school and check if they are aware of the bun and ask if they will allow me access to try and get it. If they do agree any ideas on how to catch him/her? I know that if I catch him then I'll have to then decide what to do with the bun. My two got referred aggression when a wild bun got into the garden last year so I'm not hopeful that they'll bond with another bun, plus obviously I first need to get it vet checked, neutered etc etc before I introduce them anyway.
The bun's having the time of its life with all the space but I see it sat on its own and it breaks my heart that it hasn't got a safe bed and bun to snuggle up to.
So basically ideas of what to say to the school and ideas to get it?

Awww poor bunny. I would go to the school during the day and maybe speak to the receptionist or whoever is available. I'm sure they won't have a problem with you going in to help the bunny. Do you know the school cleaners? Maybe they could help?

Hi Amber, unfortunately I have no contacts with the school and as I leave for work before 7.30 and usually get home after 6 I'm not able to go in in person. That'a why I thought email might be the best option.

Hmmm, you could do, or maybe if you ring the school out of hours, you could leave a message. I hope you can catch this bunny, I'm like you, I'd hate to sit at home knowing he/she is out there!