Abstract: The method of re-finishing an uneven opened-angle construction joint of a ceiling or the like, includes an inventive kit including a line marking device to impart two straight lines, one at the uneven line of the open angle construction, and the second parallel to the first and at a distance equal to the width of a blade of a trowel of the kit to be used in applying a refinishing material to the ceiling. Then one or more elongated guides of the kit are temporarily attached end-to-end to the ceiling along the second line. After attaching the guides, a refinishing material is applied to the ceiling at the uneven joint, by drawing the trowel blade positioned with one of its corner edges against the marginal edge of the guide and its other corner edge against the open-angle corner.