It is possible to adjust the fingers on the pressure plate while installed in the car through the little window on the bell housing, but it is definitely not a fun job. It is best to make this adjustment before the transmission is installed or while the engine is out of the car. You will have to break the swage on each finger post it order to turn the screw and you will have to rotate the engine a number of times to bring the fingers to the top in the window. You will also need some kind of a fixed measuring device.
There is a technical article about the subject that might help you.
Go to the web site of the Santa Anita A's (Arcadia, CA) at santaanitaas.org. On the home page put your cursor on "Technical reference", my name will appear in a window below, click on it. It will bring up a menu of technical articles. Scroll down to "Transmission", then to "pressure Plate Adjustment", and click. The article is a pdf file and you are welcome to download it. A photo shows a tool that was developed to measure the adjustment. You want each finger adjusted between 5\8" and 3\4", 11\16" being nominal, and you want them all the same.
Tom Endy