Easy.....

All you have to do is get into a infected slow mo lobby or fast mode lobby

And then back out and play in your own private match and play with your friends or yourself and when your done end it.

And then you can go play online if you want, and when you do that you lose your infection

but when you want it back go to your theater and find your infected match you played and click on it and load it up

then end it. After that you have your infections back...

But if u need a infection lobby to start out

MSG me ............. GT: JAY SWAGA
THank the post if it helped you