I just did this to my '65 Convertible yesterday. This was a fun little project. I am being totally sarcastic. I had to plan on how I was going to attack this. The project did come out very well though. The first thing that I did was remove the radiator. You have to do this to get to everything correctly. The next thing that I did was remove all of the old staples with a small flathead screwdriver and a pair of needle nose pliers. Once that was done, I enlarged the staple holes slightly using a 5/64th drill bit. I highly recommend this. But it is entirely up to you. It makes installation a bit easier and makes locating the holes through the rubber much easier as well. Once the holes were enlarged slightly, I correctly positioned and installed the rubber over the radiator support. Then, with the rubber correctly installed and positioned, I went from underneath the top of the radiator support and slowly located the holes from the underside. Using a small Phillips head micro screwdriver the same 5/64th diameter as the hole, I slowly poked the holes through from the bottom until I had done all twenty holes. Once the holes are correctly poked through, Now all of the holes are correctly positioned, and you can start to attack the project from the topside. With the rubber installed and all of the holes correctly placed in the rubber, You can start to install each staple one by one... Insert the staple from the top of the rubber where the 1st staple holes are. Make sure that you feel both ends of the staple go through the radiator support and you should also feel the staples exit the rubber from the bottom as well. You now have the staple all the way through the rubber and the radiator support. Now comes the bending of the staple. Using the bottom end of a big screwdriver, Use the bottom end to hold top tension on the top of the staple so that the most amount of staple ends protrude from the bottom. While still holding top tension on the staple, Bend one end completely over as far as you can go, then move onto the other side and bend that side over as far as it can go while still holding tension down from the top. If the staple is not completely closed, That's ok..because that's coming next. For completely closing the staple, I found that a flat scrap piece of thick sheetmetal about 3 inches long works really well, Just make sure that it's thick guage or something comparible. Take the 3 inch long flat sheetmetal, and put it over the staple and rubber area at top, and get a variable jaw pair of pliers and position the top jaw of the pilers over the 3 inch long sheetmetal, and the bottom jaw of the pliers over the bottom of the staple, and squeeze flat slowly. It works like a charm... Just go slow.. If you have problems trying to close both side of the staple, just close one side at a time, and it will go easier.. Repeat the procedure for the rest of all the staples.. The whole thing took me about and hour and a half to do correctly, so You'll want to take a break after doing the first few staples, and return back to it later. When you close the staple correctly using the "fold" method of closing the staple, The bottom rubber will "puff" outward actually hiding most of the staple from the bottom. Have fun! Go slow... You'll get there! My '65 had a total of 10 staples from the factory...and my '66 had a total of 6 staples from the factory. Both are Dearborn cars.
This was the method that I used... You are welcomed to try another method..
Tony K.