I'm working on a bunch of strings of numbers. These strings contain three sets of numbers separated by a space, and I would like to replace only the third part of the strings. Example:

I want to replace
"01 01 0000" --> "01 01 .1"
"01 02 0000" --> "01 02 .1"

Is there a possible way I can use a wildcards to do this quickly? I have 2 thousand lines of numbers I need to replace!

Thanks,
Catherine