1. You need TXD Workshop to add those icons, for example, search for an ak47.txd, then find ak47icon, get one of mine, for example - get ak74.png and rename it to the ak47icon, done.
2. I Used MS Paint, Irfanview and GIMP 2 to make it
3. No, I will not tell how I do that
4. If you want another new icon weapon, just mail me : P.Grajcarek@autograf.pl, I can easily make every weapon icon :)