Hello everyone

My name is Ruben, and one of my friends ask me for help on his store, this is the one http://organic-select.com, she ask me to change the minimum of purchase, if you try to buy something it will tell you that you have to buy $300 pesos in order to make the order, we need to change this to $50 pesos...
I have search for 2 days and I can`t find where to change it..

I hope some one can help me..

Greetings
Ruben Perez