Your ‘friend’ needs to get an attorney that could approach the trial attorney for DHS at the venue from where the removal order was issue to see if they’re willing to join in a motion to reopen his proceedings. If the govt attorneys are willing to join the reopening of his case will be all but certain. Once the immigration judge grants the motion they can then try to get the case terminate (the ideal result) or at the very least administratively closed.

As mentioned by others, traveling with a final order of removal opens up the opportunity for the office at your port of entry to deny you admission back into the US even if you have an advance parole.