Changing the name of a UV'ed Texture file

I am a Blender novice and am currently making scenery models for the Trainz railway simulator.
Having already UV’ed a mesh is it possible to change the name of the Texture file or in fact use a different texture file whilst maintaining the UV co-ordinates.
To explain - I have made an Old West Assay Office using a texture file called Assay_Office_Texture_V3.tga and would now like to copy this model and use it as a Bank I can substitute the Textures on the targa file but would like to name this bank_texture.tga is this possible as it would cause problems having two files with the same name containing two different sets of textures.

Thanks

Ken

Replace image on the Image menu of the UV Image Editor - I was looking in the area where the file is loaded. This replaces the file with a new file and maps to the equivalent positions - just what I wanted.

Thanks

Ken