Permission for one of your songs

Hello Rhett and Link,

My name is Miguel and I'm currenty on a group working on an independent video game, and I would like to ask for your permission to use one of your songs "Squirrel Rights" to be in it. I intend to change so that the voices sound like squirrels since the videogame is about squirrels and I thought the song fits in with what we are doing. I will make sure to credit you guys for the song, I'm just asking what else would I need to do to use it in the game avoiding any problems and make sure you guys are ok with it before proceding any further.

Thank You

Miguel Angel Mercado