If you and your ex broke up on good terms, then getting her back should be as simple as moving to where she lives, and re-initiating contact just to see if she wants to hang out for a drink. If the feelings between you two are still there then it will be straightforward from this point.
Do NOT let her know that you moved to the area she lives in just to get her back, even if that is the only reason you went there. You HAVE to come up with some other reason for the move, like you got a job offer there and it was too good to refuse. Why can’t you tell her you moved just for her?
Because it creates a scenario in which you are chasing after her, seeing her as the prize to be won. You chasing her makes her perceive her own dating market value (DMV) as higher than yours. Women are not attracted to men who they perceive to have a lower DMV than they have themselves.
To maintain your cover (of not being in town just to get your ex-girlfriend back), only contact her after you have been in town for a couple of weeks or more. If you were to pursue her a few days after the move, she’d know you’re there for her, and she’d see you as desperate too. Nothing causes desert-like dryness in a woman’s panties quite like male acts of desperation!