Is it possible to remove a scar on the back side of my head from a hair transplant surgery? If, so what is the best option?

Once a strip surgery produces a scar is performed, you cannot remove it.  The best you can hope to do is to camouflage the scar by adding hair to the scar by follicular unit extraction, applying small dots of pigment by scalp micro pigmentation, or to reduce the width of the scar by a scar revision.  Strip procedures also cause a misdirection in hair growth alignment, as well as, joining hair of different caliber along the margins of the scar. These problems of misalignment and differing hair caliber cannot be resolved.  The best solution is to avoid a strip harvest procedure entirely.  

Scar revision surgery for bad hair transplant scar.I have done this sort of revision surgery for a bad hair transplant scars for 35 years. This car is never totally remove it should be a fine line when done. See a very experienced surgeon for this