Spannerhead - good points but really the stipulations of the revised regulations actually apply. If the AMM does not specify the task, it is not an on-wing task strictly under the A-rating of your AMO. If it is in the CMM, it is strictly a shop task but could be accomplished on-wing by you if agreed by Competent Authority through the MOE etc.
Not suggesting any lack of competence -
- just that these days all is well until something goes wrong and the investigations start.