Can I get a patent on an old abandoned patent? How?

When you submit a Patent Application to the U.S. Patent Office, you are required state that you believe that you are "the first and true inventor". You may be wrong but you do believe that you are the "first and true inventor". If you were to be granted a U.S. Patent for an invention that you did not invent or that you copied from someone else, the U.S. Patent would be of no value and would not be upheld in court once the true facts were revealed. Many Patents are improvements to inventions that someone else has made, and you would certainly be entitled to a Patent for the improved portion of the invention. I hope that this helps.

No, the information is now available publicly anyone can use it so there is nothing to protect. Your best bet is to find a really good patent attorney who can argue with the USPTO on your behalf that your invention is different enough from the abandoned patent to justify granting it patent protection.

If it is the same, then no. If you have innovated beyond it, then yes.

If the abandoned application was published, it will be prior art that can be used against your instant application. However, if you file a new application comprising inventions that are not anticipated by, and not obvious in view of the old application and other prior art, it might be allowable. So it all depends.

Unfortunately - no. Once a patent is abandoned - it enters the public domain - free for all to copy.