I installed ImageMagick via Homebrew.
However, due to a bug I have with my current configuration, I need to adjust the compile flags for the formula and reinstall it.
How can I accomplish this?
Remove the existing version.
$ brew rm imagemagick
Then to edit the formula, just edit it:
$ brew edit imagemagick
This will bring it up in an editor; make sure your $EDITOR
variable is set to your preference (for me: TextMate)
Change it, save it, try installing it.
If you're comfortable with git, you may want to make a branch first, and do your edits in a branch.