I just messed up using the Gradient Mesh Tool in Adobe Illustrator.
I want to start a brand new Gradient Mesh on the object I messed up on and don't want to delete the original shape.
How can I remove the existing Gradient Mesh so that I can start a new one from scratch?
There is no effective way to simply remove a Gradient Mesh from an existing object.
So, instead you need to regenerate an object which matches the original shape but without the mesh applied.
Object > Path > Offset Path
This will create a new object which matches the shape of your original object. You can then simply delete the original Gradient Mesh object and start over on the new shape.
If you select the gradient mesh tool then hold alt/option and click the point where you inserted the mesh, it removes it.