When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I can offer this,
You will need a lift...one that allows room to move around so you can wiggle the old out and the new in. Lifts that the tires drive up on are not goona work. You need the lift that lifts by the jacking points on the body.
Good luck and wear goggles.
4-post lift works fine. I've done it and it's been done by many others. The car simply needs to be positioned on the lift so you can maneuver the exhaust as you take it off. A couple here have even backed the car up to a loding dock to swap their's. Otherwise it's a two-poster for the easiest swap or diy by jacking the rear at least 32" from the bottom of fascia to the ground (not recommended for the inexperienced). With an A4 you'll need to remove the passenger-side fuel tank shield.
You can see that it's easily done on a 4-poster.
Here's a couple of shots of a swapdone with jacks.