A bearing assembly for a wind turbine, comprising; a bearing comprising an outer race , an inner race rotatable relative to the outer race , and a plurality of roller elements positioned within at least one raceway defined between the outer and inner races , at least one of the outer race or the inner race defining a radial opening ; and, at least one ball plug positioned within the radial opening of at least one of the outer race or the inner race , the at least one ball plug being removable such that the plurality of roller elements can be inserted between the outer and inner races , at least a portion of the at least one ball plug comprising a tapered cross-section, wherein the tapered cross-section is positioned between an outer portion and an inner portion of the at least one ball plug so as to define a transitional region thereof; further comprising exterior retention means arranged at or adjacent to a distal-most end of the outer portion of the at least one ball plug ; a plurality of O-rings arranged circumferentially around the inner portion of the at least one ball plug , wherein the inner portion of the at least one ball plug further comprises at least one annular recess, the plurality of O-rings arranged within the at least one annular recess; and the plurality of O-rings being aligned in a longitudinal direction of the at least one ball plug ; and further comprising an anti-rotation device in contact with an inner surface of the radial opening , the anti-rotation device extending perpendicular to a longitudinal axis of the at least one ball plug and engaging the outer portion of the at least one ball plug so as to prevent rotation thereof. a bearing comprising an outer race , an inner race rotatable relative to the outer race , and a plurality of roller elements positioned within at least one raceway defined between the outer and inner races , at least one of the outer race or the inner race defining a radial opening ; and, at least one ball plug positioned within the radial opening of at least one of the outer race or the inner race , the at least one ball plug being removable such that the plurality of roller elements can be inserted between the outer and inner races , at least a portion of the at least one ball plug comprising a tapered cross-section, wherein the tapered cross-section is positioned between an outer portion and an inner portion of the at least one ball plug so as to define a transitional region thereof; further comprising exterior retention means arranged at or adjacent to a distal-most end of the outer portion of the at least one ball plug ; a plurality of O-rings arranged circumferentially around the inner portion of the at least one ball plug , wherein the inner portion of the at least one ball plug further comprises at least one annular recess, the plurality of O-rings arranged within the at least one annular recess; and the plurality of O-rings being aligned in a longitudinal direction of the at least one ball plug ; and further comprising an anti-rotation device in contact with an inner surface of the radial opening , the anti-rotation device extending perpendicular to a longitudinal axis of the at least one ball plug and engaging the outer portion of the at least one ball plug so as to prevent rotation thereof. <EOS>