You don't turn the actual files into a *.ktp file. For instance, if I were to make some scripts for the game, I would need to use the compiled *.ncs files. The *.ktp files are KotOR Tool Project files, they manage the files contained in a mod. So, if I had some files to be compiled to a module and some scripts, the *.ktp would 'tell' KotOR Tool to compile the module files with the module compiler and the *.nss source code files with the NWScript compiler. In a nutshell, the *.ktp files are KotOR Tool-related files that manage mod projects, they're not mods unto themselves.
If you want to create a KT project though, go to Tools->Open Project Manager