Do I need to remove my old mirror housing to install this?

No. This glass swaps directly into your existing mirror housing at the factory mounting points. You're just replacing the lens, not the whole assembly.

Will this glass work if my mirror housing is cracked?

This is glass only. If your housing is damaged, you'll need to repair or replace that separately—the new glass won't seal a broken housing.

Does this come with adhesive or mounting hardware?

Glass lens only. Check your factory housing for existing clips or adhesive points before installation—mounting method varies by your specific mirror assembly.