No problem!
You just install .net (i use the .net 3) and after that, launch TT customizer
Open a theme you already have in your computer (the skin.ini in the folder)
You have now the skin open in front of you!
After that, you can change text color and transparency of headline.
To modify pictures, the best way is to create them in your favorit photo edit (like photoshop) and save them in BMP. Replace the original by your creation.
Same name and same size
for exemple : top picture is bgup.bmp in 256x16 pixels