Once the bottom is covered, cut the top piece using a metal straightedge so you're starting with a straight line. Lay the piece in place and tack the two ends.

Now turn down the heat on the iron. With LOW heat, go over the seam. Increase the heat a little and repeat. Keep doing this until the seam is properly sealed.

An alternative method is to spray the adhesive side of the covering with MonoKote Trim Solvent (if you're using MonoKote) or Xylol (if you're using Ultracote). Lay the piece in place, squeegie out any excess liquid and let it sit overnight. You can touch it up with an iron the next day.

If you get any color bleed, you can remove MK color with Acetone.