How can I make custom sounds for custom weapons (SWBF2)?

[Gui de Machaut]

Hi, my friends!
I'm trying to put downloaded .wav sounds in my custom weapons, but its not working.
I read all the tutorials that I found. I followed all steps, but without succes.

Can you help me, please?

[Gui de Machaut]

ps. I will be very grateful if someone can explain me step by step how to add new sounds to the weapons. I've been trying for days!