Can't seem to adjust back to Alto. :( Help

[TokyoRain]

I am a proud Bari player and my choir teacher (used to be anyway) has scheduled me to play Alto in her choir concert. How can I adjust back to being able to play Alto in a few 2 weeks (I played for 3 years prior so it's somewhere in me I just can't find it) and not lose my Bari "mouth".

[DanCraven]

Practice every day for 2 weeks...

If you have to play, you have to play, and you'll sound better if you practice. There's no mystery to it. You won't lose your bari chops in 2 weeks.