To answer your question, it is fairly staright forward. The last one I did, I bought a generic vinyl top that had about 3 extra feet of material all around. I trimmed it leaving about 6 inches. I measured the sewn in seems and then measured and marked the roof. The skill involved lies in keeping the seems straight from front to rear and centered side to side. I used a 3m roll on glue. Let it tack up as instructed, the first time I applied the top too soon and it bubbled, necessitating me to pull it back up and reapply, didn't hurt anything, and was just a small section, just took some extra time.
Work from the center out. Draw a line where the chrome goes so you know where to trim. Do not stretch too tightly, the sun will shrink it and pull it out of the gutters and above the chrome trim if not careful.
Again the skill and quality work lies in keeping the seems straight and not trimming off too much material.
