Hi,
Such scars are notoriously difficult to erase. Fractional carbon dioxide laser may help improve the skin texture somewhat but the scars are likely to be still quite visible even after several treatment sessions.
Patients often ask me if surgical skin grafting is possible but this option replaces the linear scars with a much more obvious skin graft and is thus not recommended at all in my opinion.
When current medical/surgical techniques fail to offer significant benefits as in your situation, do not abandon the more practical approach of simply covering it up with long sleeves or with a corrective foundation whose colour most closely matches your skin.
Take care!