People on this thread are talking about 2 different issues. One is separating the ball joint from the lower control arm. This can be relatively easily accomplished with the Harbor Freight tool phen8tk refers to, or the much more expensive Acura Service tool referred to in the shop manual. The second issue is removing the ball joint from the steering knuckle. This is pressed in, and it's a VERY tight fit, at least on my '07. Normally, this would be done on the car with a tool resembling a large heavy C-clamp that you can borrow from places like Advance Auto Parts. However their kit does not contain the adapters required to do the job on a TSX. The factory service manual is silent on the part numbers of the needed adapters because apparently, when it was printed, the ball joint was not available as a separate part but could only be obtained already pressed into the steering knuckle as a very expensive assembly. I located some Acura adapters on-line, but the info available did not specify which adapter was for which Acura model. I guessed (wrongly) and ended up paying for something that turned out to be useless. I ended up taking the ball joint/steering knuckle completely out of the car and pressing the ball joint out with a hydraulic press. However the geometry of the steering knuckle prevented me from being able to press the now ball joint in that way. I inquired regarding the correct adapter part numbers at my local Acura dealer, but they said they received their adapters as a kit for all Acura models, and they just test fit them to the job at hand until they found the ones that worked, and couldn't tell which one was for which model. I ended up taking them the steering knuckle and new ball joint to them and they pressed it in for me, charging what I thought was an excessive amount for the service.
So now the ball joint on the other side has started to make the same noise that I eventually localized to the driver's side lower ball joint, and I'm revisiting the issue of attempting to obtain the correct adapters. I contacted Acura Client Relations, and they were completely useless, referring me to my local Acura dealer. Currently, I'm trying to get this info from some on-line Acura part dealers. If anyone knows these part numbers, please post.