Hypertrophic scarring is not treated with dermabrasion
The best treatment for a hypertrophic scar is cortisone injections and silicone gel sheeting. Hypertrophic scarring is not treated with dermabrasion, as dermabrasion will simply make the hypertrophic scar worse.
I do not recommend dermabrasion as it may leave permanent discoloration which may be worse than the actual scar itself. I would start with cortisone injections to improve the hypertrophy and improve the color of the scar. Once improved as much as possible with the cortisone injections, there are certain laser treatments which may then help improve the texture and color further. I recommend you consult with a board-certified dermatologist experienced in treating scars.