Texture creation

What part do you need help with? The recolour or the actual texture making? For the first part, you'll need GCFScape to extract the textures you want from team fortress 2 materials.gcf (found in your steamapps folder) if you're using photoshop, install The VTF Plugin and edit the textures as you please, otherwise, you'll have to first save the textures as .pngs via VTF edit and edit them with The Gimp, a free, advanced Image Editing Program then doing the reverse with VTF Edit. Now you just have to install!

This Tutorial also covers the whole process well.