[Gimp-user] brush editor

[Helen]

I created a brush with my signature, but somehow, it
is huge.  I'd like to make is smaller. A read in a tutorial
that only a parametric brush can be made smaller, but
I find nothing on how to turn this into a parametric
brush.  Can I get some direction on how to proceed?
Thanks.
Helen, using Gimp 2.2.4  with SuSE Linux