Does this come with a backing plate and adhesive?

This is the glass lens only. You'll need to verify whether your existing mirror housing bracket and backing plate are reusable before ordering — if those pieces are cracked or warped, a full mirror assembly may be a better choice.

How is this mounted to the mirror housing?

The lens seats directly into your factory mirror bracket using existing mounting tabs and holes. No drilling required if your housing is intact.

Can I install this myself?

Yes — removing and reinstalling mirror glass is a DIY-friendly job. You'll need basic hand tools and may want a heat gun to gently release any old adhesive on the backing plate before fitting the new lens.