What are my least invasive options to raise a hairline?

It is difficult to remove or undo a bad hair transplant.  You may consider electrolysis but you would need to see a doctor for a better assessment.

Many times, hairlines that were placed too low during an initial hair transplant can start to appear unnatural as one ages.  This is the case with you.  We have patients come in routinely to have this situation improved.Unfortunately, you named in your question the most common procedures that we do to fix this issue.  FUE is commonly done if you are interested in saving hair and using it other areas.  Laser hair removal would probably be the least invasive but takes a number of sessions before all of the hairs are gone.  Finally, waxing and plucking are options but are painful and can take much longer to remove the hair.I would focus on a combination of FUE for the larger grafts and laser hair for the residuals.

The least invasive option is a hairline lowering hair transplant. This may be your only option if you already had hair transplants. See web references below

Were grafts placed too low in previous hair transplant? You mentioned you do not want FUE removal and I understand that as it does leave visible scars. The hairline can be raised but the tissue removed will leave only a small scar that is not visible if done properly and you wear your hair at least 5/8 inch long. Please see link to scar repairs to help you understand how it can be accomplished.