IMO, the task is not complex at all. "New Project..." | "Uninstall Include Script...". Then add whatever you would like to do in your custom uninstall. The IDE generates all the default script lines for you in the standard custom uninstall. Add this newly created uninstall .sbi to your main script, compile and you are done.
Very often, adding lines to the uninstall .log is simply not enough. You can use ALL script functions (except Install Files of course) in a custom uninstall. Similar to the attached...
Just let me know if you need more help.
Friedrich