P Trap Question

I know that there must be an easy way to do this, but I'm not sure what is OK and what is recommended. I know that I can cut the tailpiece to make it shorter but the trap is still in front of the tailpiece. Can I reverse the trap so that the short end is in front? I think it would result in more water in the trap, and I don't know if that's a problem. Then would I offset it and use a couple of 90 degree fittings? How does a real plumber do this?

Don't try to turn the trap around: the connections won't work, and a deep trap drains slowly.

Off set at the wall with a 22½º or 45º, then swivel the trap over to line up.

Thanks for the advice, Jimbo, but that raises a new problem. I assume that you're talking about removing the waste arm (if that's the correct term for the pipe coming from the wall) and installing an offset fitting there. Unfortunately, I haven't been able to remove that pipe. It's a slip joint connection, but after taking the nut off, I can't get the pipe to budge. Is it possible that it was glued in? If so, is there a solvent to soften that glue? Other ideas?

Seeing as it's abs coming out of the wall someone probably overtightened it and it is clamped down hard on the tubular...
Not uncommon... Brute force properly applied and in the worst cast gluing on a new slip joint adapter which may be needed anyhow if putting on an elbow.

If a longer waste arm will miss the tailpiece you can always go with a longer waste arm and swivel the trap back to connect it.

I'm still not sure what to try next. I tried pulling the waste arm out while moving it side to side; it didn't budge (and yes, I first removed the nut). I then tried turning it with a pair of Channelocks and stopped before the teeth punctured the pipe. Again, it didn't budge. I'm also a bit confused about how to offset it at the wall. Assuming I can finally remove the waste arm, do I use a short extension tube to connect the 45 degree fitting at the wall to the slip joint adapter? If I remove the slip joint adapter (how do I do that?) is there a 45 degree slip joint adapter that I use instead?