I see this less as an outright rebuild & more as an overhaul of some positions.
With a new staff, and new philosophies, you're going to have to make some roster modifications, but we've still got a solid nucleus of relatively young talent. Sure we could use another DE or DB, but our D-line & secondary are hardly weaknesses. On offense we need a QB & another WR (could use a TE) but we've got a pretty decent OL, an elite RB, and a #1 WR.
Injury (Chandler), age (Barnett, Wilson, Kelsay), and disappointing performances (A. Williams, Sheppard) have taken their toll, but how many of those guys were foundational players you build around? Most were role players, stop-gaps, or unproven prospects, none of which should be too terribly difficult to replace.