unfortunately, there's no easy way to do this.
you have to have the following
1. a BLANK copy of the texture where the ship's name and registry would go
2. an Art program capable of using and modifying Targa format images (.tga)
3. a copy of the appropriate fonts used for the registry lettering and numbering
experience using the art program, some skill in 'photoshoping', and a model viewer help get the look absolutely right