How can I persuade my mum to let me miss school when we dont have lessons that day?

My favourite band in the whole entire world are coming to my town next week for a radio interview, i know exactly where the studios are and i know they're meeting fans. my town isn't very popular so there won't be too many people there. My mum already agreed to it but that was before I realised I had school that day. That day is the day before we break up from school though and there are no lessons there is just staff vs students rounders, i won't be playing and there is really no point being there then after that has finished theres clearing up the form room, i can clear my stuff up earlier in the week. there is actually no point being at school that afternoon so how can i persuade my mum to let me miss it? However another problem is that our school is on the top of a big hill and most people go down in cars, how can i persuade her to let me and my friends walk down and then to the station?? the hill will be very quiet!! if i did go to school that afternoon we would get to the radio station but 10 miniutes after they would have left :/ how can i persuade my mum to let me and my friends miss the afternoon and walk to the station and meet my favourite band EVER?? we have no problem catching trains/getting home, its just missing school.. how can i persuade my mum?? THANKS :D XXX