http://tf2.explodingjelly.com/create
The site supports .GIFs and transparency, so it'll save you the effort. Real time saver and relief.
Here's the complicated process of what you do though.
[list type=decimal]
[li]Paste both the .VTF file and the Texture file in this location after uploading or downloading them.
C:\Program Files\Steam\steamapp\Steam username here
EX:
C:\Program Files\Steam\steamapps\fallenpixels\team fortress 2\tf\materials\vgui\logos
[/list]
THEN BOOM. Done, Billy Mays style in 1 easy step.