If you have planned your route to the Italian Alps via Innsbruck Airport, you won't have any trouble finding your way to Livigno.
Innsbruck is one of the stops of the direct Livigno Express transfer, and the distance between Livigno and Innsbruck is the shortest among the possible options. You can check the schedule of the Livigno Express and reserve seats on their website. The same express service can take you to Livigno from Milan as well.
Additionally, from Milan, you can take a train to Tirano (details and schedule can be found on the state railway website), and from there, you can take a bus to Livigno (information available on the company's website).
If you have your own or a rented car, you can reach Livigno via highways from Zurich or Milan. However, keep in mind that in both cases, the road goes through mountain passes. Moreover, the route can be quite intricate, so you will need a road map and a reliable GPS navigator.
