This is probably the most annoying thing in Eagle. You need to disconnect the package from all devices it is in use by in order to add and remove pads. You can however fix geometries and even naming while everything is associated.
Yeesh… so if I had a Dip8 package with a hundred odd configs and I wanted to modify it slightly, I’d have to disconnect all of the 800 pins then reconnect pin by pin, while at the same time risking stuffing up any existing schematics and boards that use that land pattern???
Looks like I have to be very very careful and just make sure I get it right the first time. Better to learn the lesson early on… thanks theatrus