When I do something similar and the pieces aren't held together by much seam, I rip out only the intersections where they meet. Sew each seam the proper width, then re-sew the intersection. This will be one quilt that will NEVER come apart. Note: Some people would rather just take the whole seam out, because you will be working with all that material each time, and you do have to be careful to pull the extra material out of the way of your new stitching seam. I would much rather have the added strength of 2 seams, and I don't have to worry about accidentally moving my design around...and yes, that has happened. lol Bring out the ripper again!