1. Thread your tapestry needle (a fat, blunt needle with a large eye) and align your pieces next to each other one piece is vertical and the other is horizontal. 2. (Slide 1) Slide your tapestry needle vertically between two "v"'s of the vertical knitted piece to grab the horizontal "bar" behind the stitches. 3. (Slide 2) Slide your needle behind a whole "v" of the horizontal piece. 4. (Slide 3) Repeat steps 2 and 3 from the right and left sides. Since rows and columns are of different length, every few stitches you may need to skip a horizontal "v" to keep the two knitted pieces even. 5. When you pull the yarn tight, the stitching completely disappears!