How to replace sprite assets with a sheet made with TexturePacker?

I'm hoping @CodeAndWeb replies, but thought a publicly posted question could also help others:

If I made a game and then decided that I was not happy with the way the sprite packer packs everything... and wanted to replace it all with a sprite-sheet published by TexturePacker, how would I go about this?

Will I have to re-assign every sprite object a new texture reference?

What potential problems could I encounter?