Installation of Convertible Top - Can be done off the car?

Hi there.

I took the convertible top of the car together with its old (torn) vinyl before the restoration started last August.

My ques is, can i just send the convertible top mechanism (without the car) to the shop and ask them to change the torn vinyl with a new one and then I install back on the car myself? Is this advisable? Or it HAS to be done ON the car?

Appreciate your comments/advice on this.

Thanks.

Syed