I need to remove p-trap elbow, glued to drain pipe 40 years ago. It is leaking and there is not enough drain pipe left to just cut it off. I would be even hard to drill into cement around drain pipe to get more of it out to glue new p-trap elbow. Any advice will be appriciate. Thank you very much.

You didn't say what fixture the "P" trap serviced. I'm guessing bath tub. Correct? You don't just remove the elbo. You cut out and replace the entire trap. If you have to chip cement back to get more pipe to couple to and extend then that's what you'll have to do. Let me know if there's more questions.