Phrases or idioms for rebuilding something from the ground up [closed]

Solution 1:

I suggest

Start from scratch

to begin from a point at which nothing has been done yet

Nothing like this had ever been done before, so we had to start from scratch.

OR

Go back to the drawing board

to start over

The company went back to the drawing board to make a better product.

[Merriam-Webster]

Solution 2:

Another useful phrase for starting over is:

Go back to square one.