Deleting specific characters

I have a specific issue that I'm trying to figure out. I'm sure there's a way to do this (perhaps even some terminology I may not be familiar with) so hoping to find some assistance.

I have an excel with 10,000 line items. each cell has series of numbers:

113320_150752
113320_150752_123hjsdf
113320_150752_2349728
113320_150752_
113169_14223_

Above is a small sampling. However, I need to be able to scan through a list of 10,000 of these (each in their own cell) and remove the second underscore IF there is nothing following it.

So in the above example, the 4th line, I need to be able to remove the "_" after 150752 because there's no characters following it. Same with line 5.

I can't do a find/replace, as I don't want to mess with any underscore unless it meets that specific criteria. Is there a formula, or macro that can be built for this? It's something I do daily.

Thanks for any help!