It depends on what you mean by "fixed". If it's a genuine antique than the areas are preserved by hand stitching tulle over the original fabrics. If you want it to use, there are many ways to accomplish it. If there are only a few areas, you can hand applique butterflies, flowers etc. over the torn/ripped pieces. If the whole block needs replacing you can snip out the old square (being carful to leave the seam allowance intact on other blocks) and lay the new block under the blocks surrounding it and hand stitch the seams back in.
It is sometimes hard to find fabrics that have the correct faded appearance of the surrounding blocks. You can sometimes use a modern fabric and use the reverse or wrong side of the fabric to better camoflage the repair. Good luck!