The project rename option only renames the underlying project
files (e.g. .hhp, .ali, .hhc, .hhk, etc.) not the actual output or
topic files. If you are outputting a CHM file you'll find the
rename process leaves the original CHM file unchanged. For example
renaming the project NebraskaProject to Nebraska leaves the CHM
file with it's previous name and therefore the external links do
not change and will work.