Walk one block east on Lake to Wabash, the one block north to Wacker Place. Go west a half block. Takes about 20 minutes. You can also take the 20 or 56 buses east on Washington. On either bus, get off at Wabash and walk three blocks north to Wacker Place.
Taxis are also available.
The drive curves with the river and will take you directly to the corner of Wabash and Wacker Place. A total of 13 blocks. You can also catch the 60 or 151 bus on Jackson. Either one will take you east to Michigan Avenue, then turn north. Get off at Wacker Place.