How can I get rid of these under arm scars from shaving? (Photos)

Thank you for your question and posting pictures.  It looks and sounds like you have post inflammatory hyperpigmentation.  Since you are a Skin Type IV-VI, we would not recommend any IPL and some other energy treatments for you. 
We have been very successful using the PicoSure laser with the FOCUS and / or Flat Lenses eliminating hyperpigmentation with a series of treatments.  FOCUS lens treatments have the extra benefit of reducing fine lines, wrinkles and scars.  This is one of our go to treatments for patients older than 40 and worried about the signs of aging.  This laser is safe for all skin types.  Start with sunscreen every day!  Once you have treated your hyperpigmentation to your satisfaction, you will probably need a follow treatment every 6 to 12 months depending your level of re-pigmentation.  Best of luck.