{1} means "1 instance of the preceding element", which is redundant. Perhaps you're referring to {1,} which means "1 or more instances of the preceding element"; the + operator is equivalent.
You can solve your problem with the following, replacing all underscores in the expressions below with spaces.
Find what: __+ OR: _{2,}
(Both mean "2 or more spaces")
Replace with: :_
Last edited by ak47wong on Sat Sep 28, 2013 11:36 pm, edited 1 time in total.