How can I get TF zombies in SFM??

[Reaper]

I have tried to get some tf zombies looking in this tutorial, but when I finish them they look transparent. I have looked in many sites, but there is nothing. How can I fix this?? Is there another way to get tf zombies??

http://www.youtube.com/watch?v=64lKrw7hRgw

I have seen some videos in which some tf zombies appear. Does someone knows how to get zombies that are like the ones that appear in this video?

http://www.youtube.com/watch?v=hMmuP1glj8M

[Pte Jack]

add the command "$mostlyopaque" to the zombie alphatest vmts, I think that is the only one you have to add it to.

[Reaper]

Początkowo opublikowane przez Pte Jack:

add the command "$mostlyopaque" to the zombie alphatest vmts, I think that is the only one you have to add it to.

Forgive me but... how do I do that?? Just explain it a little bit so I get an idea.