Hi Ellen!
I had an extreme case of overabundance with my first child 10 1/2 years ago.
 I had to wear 6 breast pads at a time and had to change bras constantly,
squirted milk clear across the room and my daughter was slow weight gain,
projectile vomitting and constantly hungry and fussing at the breast.  I went
to my first La Leche League Meeting and the leader there suggested that I
nurse my daughter, on demand and until she decided that she was finished,
using the same breast for a two hour period and then switching to the other
side for the next two hour period.  This helped very little so we tried a
three hour stretch, then a four hour stretch (remember - I had enough milk
for an entire nursery full of babies).  Within a few days, my milk supply
decreased to meet demand and from there on, with her and with the rest of my
children, I made sure that I nursed on demand until the baby was satisfied
and came off the breast on his / her own and avoided switch nursing which
increases milk supply.  I still had to wear breast pads but for minimal
leakage.
Since then many, many mothers attending our meetings, have been helped by
this same information.

Hope this helps!
Leona Simoes, LLLL