You don't repair them from the back. You remove the woofer from the front. Agree with the others in that they are not worth salvaging. You would be lucky to get $20 for those if *working*. With a bad driver they are not worth anything. I bet the crossover consists of a single capacitor soldered to the tweeter and nothing else. Vintage speakers only have value if made by a well known reputable company which will appeal to collectors and nostalgic fans. A no-name old speaker is just that and nothing more. Play around with the components for fun if you like but you will never get more money out of them than you put into them.
After I gave my daughter the old KEF speakers that I rebuilt, I brought a pair of 3-way towers home that she was using. I hate binning gear that can still be used, but these were an off brand and had a bad driver with particle board cabinets covered in vinyl. Simply not worth any effort. I put them on the curb and no one even looked at them to take away for free, so out with the trash.