From Monzen-Nakacho (門前仲町) to Komaba Todai mae (駒場東大前)

Tozai line (東西線): Monzen-Nakacho (門前仲町) → Nihonbashi (日本橋) 

Ginza line (銀座線): Nihonbashi (日本橋) → Shibuya (渋谷)

Inokashira line (井の頭線): Shibuya (渋谷) → Komaba Todai mae (駒場東大前)

See this video for changing trains at Nihonbashi (日本橋) .

See this video for changing trains at Shibuya (渋谷).