Once you open this program, click on the 'format' option (on the
menu header)
then click on 'bullets ... '
from here set it the way you would like it to be.
I have the same set up as you, and can find no way to promote/demote a level in impress, there is no bullets tool bar in impress. I am just installing 4.1.6 and will check that.
I could copy and paste from writer with a desired outline, but then could not change anything.
Steve