A lot of vinyl tops are applied by spraying the glue to both surfaces, but if you don't have the proper spray equipment, then brushing it on is just as good. You'll need about two quarts for a roof this size. Apply the contact cement to both the roof and the top about one third of the way across the roof and all the way from front to back. Spread the cement as thin as possible without leaving any gaps. Definitely no puddling allowed. You'll have about 5-10 minutes to work each area.