My advice would be to f*ck getting the train. Say the match finishes about 9.35/40, you've got 15 minutes to get there, which you can't do walking. Plus you're going to have to watch you're back all the way there cos
a: you'll have to walk near the Meadows estate
b: we all know what happened last time City fans walked back to the station 2 years ago
I think you'd be better off going in The Larwood next to the cricket ground after the game, have a few pints, then get a taxi back to Leicester. It'll cost about £30, but between 4 or 5 of you that's alright if it saves you a kicking.