You steep one bag in hot water like you would for regular tea. At least a few minutes, but sometimes I leave it much longer. Pour the tea into a pitcher and add water (one gallon total for me). Add whatever mio/Crystal light you want (I use lemonade, blackberry lemonade, and strawberry lemonade, but you can use whatever you like in whatever amounts suit you as far as taste and sweetness).
I make a gallon up before bed every night, so it is cold the next morning and I don’t have to worry about adding a ton of ice to chill it.
I should mention that drinking that much liquid every day takes some getting used to. It will probably seem pretty difficult at first. You will also make more frequent trips to the bathroom than you are used to, so keep that in mind.