There is a constant need for rebasing implant-retained overdentures because of the inevitable continuous absorption of the underlying residual ridge, which results in a lack of proper occlusion and possible rotation of the denture around the retentive components. This step-by-step article describes all of the clinical and laboratory procedures needed for rebasing a mandibular implant overdenture retained with a bar on two implants, securing an accurate fit. This procedure can be applied successfully for rebasing overdentures with different superstructures (ball attachments or magnets), and for replacing worn or damaged retentive components and matrices.