A flexible trephine includes a flexible section that is formed of a spring member. The trephine is tubular and includes a central passage so that the trephine can coaxially fit over a longitudinal implant while force is applied to the trephine. The trephine has an annular cutting head for removing bone that surrounds the implant, so that the implant can be removed. The trephine is urged in the longitudinal direction of the implant while fitted coaxially on the implant so that the implant can be separated from the bone. The flexible section of the trephine allows the trephine to conform to and follow a bowed implant. The cutting head can include multiple teeth or a single osteotome.