Getting uncommon infected to spawn (L4D2)

[someguyihate]

I basically want all the uncommon infected (except for clowns) to spawn in the map I'm currently working on. I've had absolutely no luck finding information on how to do this.
Can anyone help?

[Firegod522]

[url]http://developer.valvesoftware.com/wiki/Left_4_Dead_Infected_Populations[/url]
?

[someguyihate]

Am I able to add a custom population to population.txt or do I make a new text file and package it with my campaign?

[peatear]

Check under #2
"How To Use Them In a Map"