Its for CFS 1, does that matter?
Yes. For CFS1 you would be better off with ConvR8 from the same site. It will convert & save the commonly used AF texture format. Treat them as R8 & save out using the appropriate file extension. (e.g myplane.0af)
Some later CFS1 aircraft have 8 bit BMP textures which can be read directly by Photoshop. These can also be converted back to the correct 8 bit format with ConvR8.