Any advice on how I can improve this scar 3 years after tattoo removal?

this is best treated with a scar revision and then laser treatment. although an alternative is to do fraxel or halo in a series of treatments with PRP. microneedling and microneedling RF will do very little.
there are many options for old 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 +/- radiation
see an expert.
Best, Dr. Emer.

Dear Mgt 1,
it is hard to tell for sure without an examination. Generally speaking, a combination of laser treatment, microneeling, prp provide good results. If you are considering a treatment, I would suggest you to consult a board-certified plastic surgeon. Only after a thorough examination you will get more information and recommendations.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery