If you want to keep your original raw settings in a file, you can make a virtual copy and change your settings for a new version. Otherwise, simply adjust the sliders in LR's Develop module any way you want. Raw files are forever editable. When satisfied, you can export in JPEG or another format as you like, and continue with the same raw file, making version after version of it. There's no need to touch the "import" button. Just re-select the raw file in either the Library or Develop module.
I processed a RAW file. I exported the Jpeg file. I want to process the RAW file a different way
If you have already worked on the Picture and wnat to reprocess it , start using the Virtual Copies of your raw files.
Hope that helps