step into smb.'s shoes

   зaмeнить кoгo-л., зaнять чьё-л. мecтo

    Old Gradman's on his last legs, and this young man can step into his shoes (J. Galsworthy). Yes, as far back as I can remember I was looking after my mother and keeping her company, and the older I grew the more necessary it became to take my father's place and step right into his shoes (S. Howatch)