I read that someone was advised to do the following regarding that person’s ex:
Get her to take you back.
What does that mean?
As has been pointed out already, "get her to take you back" means advising you to take some action so that your ex comes back to you in your relationship.
Here's a usage of this phrase from this ehow link-
How to Get Her to Take You Back
By Kelly Smith, eHow Contributor
This is a summary(reasoning) of the title used above-
You want her back, but you don't know where to start, and you may not even know how you lost her in the first place. There are some surefire ways to get her back, providing you didn't do anything unforgivable in the first place. It takes more than just saying you're sorry or begging for forgiveness. The average woman wants a better attempt at winning her love back than a lame, "I'm sorry" or "I didn't mean it." She wants action and follow-through to show her that she made the right choice being with you in the first place.
Hope the meaning is clear to you now!