Decals are easy to apply when they don't exceed 24 inches in width so what's a girl or guy to do when they order a super wide decal. Begin by looking at your decal. If there are spaces or openings where it can be cut into sections that is the best alternative. Along the top edge - tape the long/wide decal to the wall or surface. Then make vertical cuts beginning at the bottom of the decal up to the tape line. You can then apply the decal in sections.
If your decal is continuous such as in the vine monogram and has no natural breaks, then it's best to use the center-hinge method of application as shown in the video below. Now grab a glass of wine, watch the video, relax and then go tackle that decal.