I had a bull horn lip lift, can I do another one and remove the scars? (photos)

I agree, more skin can be removed and the scar is currently visible. I would consider getting another opinion form another surgeon who is experienced with this surgery. In addition, inquire about whether or not the surgeon has a CO2 laser. This laser is an excellent way to diminish the appearance of incisional scars without surgery.

I would do lsers and at home dermarolling (use the MTS roller with anteage ampules, cosmelan 2 cream and IS clinical shield -- see link to emeragecosmetics.com where we do free skincare consults daily). I treat this often with lasers.
there are many options for  scars:
1. vascular lasers (yellow laser, vbeam, excel v)
2. fractional lasers (fraxel, erbium, co2)
3. microneedling/PRP
4. silicone based scar gels with growth factors
5. excision 
see an expert.
Best, Dr. Emer.

Bad scars with Bullhorn Lip Lift-Correction? The closure and scar can be revised by a VERY experienced Lip Lift surgeon! Two issues-first -This is a scar that needs to be removed and properly closed. Second-the scar on the outside of the ala is often a bad one which is why for 46 years I have done the M type without those alar incisions. Your lip can be raised at the same time.

Your scar line is not that wide and certainly there is room for more upper lip reduction. It would be of value to know how much in millimeters skin was removed in the last surgery and how it was closed. There is a reason the scar turned out this way and whatever plan B is it should not be the same as Plan A.