Yes, this can be completed: 
  1. Go to Core > Settings > School Information > Years & Terms > Change the current year to 2017-2018 (Last year) 
  2. Then go to Core > People Finder > Relevant User > Access >Withdraw the student as a Past Student
  3. Re-enroll the student into 2018-2019 (This should give them the incoming student role)
  4. Click the Pencil and select to Undo Incoming Student Enrollment
  5. Go to Enrollment Management > Admissions > Admissions Management > Enroll/Inactivate Candidates 
  6. Follow the prompts/filters to select and inactivate the candidate
  7. Change the Current year in core back to 18-19