Yeah, dead easy--as long as you can cut and paste folders.
The RivieraLine folder that has been installed to
..\RailWorks\Assets\RSC\RSC\
needs cutting out and pasting in to
..\RailWorks\Assets\RSC\
essentially just a case of moving it from the second RSC folder to the first.
Once everything has been moved that second RSC folder should be empty, and can be deleted.