If you want to rotate the sketch, redefine the original feature. While in "sketch" mode, select save. Exit the feature. Edit the feature again and delete all entities of the sketch. On the top tool bar, select "Sketch", then "Data from file". Select the sketch that you just saved. Scale it at 1.000 and enter the angle that you want it rotated. Re dimension it from existing entities, and you are done.
If other features are dependent on any of the current entities, insert the rotated sketch before deleting the original entities, but place it out of the way from the original entities. Highlight the new rotated entity, then on the top tool bar, select "Edit" then "Replace". Now select the original entity that is not rotated. After "replacing" the old with the new, delete the remaining original entities, add dimensions to relate the new sketch with existing features, and you are done.