lippy,
For the transmission tunnel side panel, first I carefully drilled out the holes to the correct size for the pem nuts, without bending the flange. Don't try to drill out too much at one time, or it might catch and bend the flange. Then I laid the side panel down on a bench, so the under-side of the top flange faced up. With the PEM nuts in position, I used a hammer to gently tap them into place, it was very easy to do.
For a panel already attached to the car, a different technique would be needed. Once the hole size is correct, one might be able to use a 'C' clamp and a few scraps of wood or parallel jaw pliers to seat the PEM nuts. However, always best to experiment on some scrap sheet metal the same thickness as in the car, before attempting it on a Cobra.
Perhaps some of the other guys that have used PEM nuts have other suggestions. All that being said, always keep in mind that the sage advice of Bob P. is hard to beat …
