I got a better flight IAD-FRA-LIN so I'll be deplaning at LIN.

I was told it's easy to take the bus to BGY, the airport outside Bergamo, then a bus from there into Bergamo.

So far I can't find a bus LIN-BGY. Anybody know of this bus?

Or if it doesn't exist, is the best route to head to Milan Centrale and take a train from there?

Or can I just go to Lambrate station, near LIN, and onward to Bergamo?