Did both sides tension struts and ball joints this Sunday. The bushings were really worn out and cracked. It went pretty well. It took me 1h30mns to do both sides including jacking up the car and I really took my time. I first removed the front big bolt (it is a 21 metric). I used a flat 21 metric wrench on the inside to hold the nut and a 21 socket with a long lever arm wrench on the other side. I then removed the ball joint side of the arm using a torx inverted socket. The 2 torx bolts that hold the ball joints are not very deep so you really need to be sure that your inverted socket has good grip on the bolts in order not to strip them as Weasel and Flyingmachine mentioned quite rightly. You need to turn the wheel in between the first and second bolt to have a good access to them. I rented a slide hammer at Autozone but never had to use it. The ball joints came pretty easily with just some slight hammering on the tension arm that I kept attached to the ball joint. Since I was replacing both the arm and ball joint I did not need to remove the old ball joints from the old arms but I did remove one to see how difficult it was. With a Pitman arm puller it came out very easily.
Now the results. The X drives better now. It has a better and more sturdy feeling. However I still have a clunk/rubbing noise though that is obviously not coming from the tension arm bushings or ball joints unlike I initially thought . It makes more of a clunking sound when driving even on flat surfaces and it makes a kind of rubbing sound when turning wheels when the car is not moving. I believe both sounds to be related to the same problem but I may be wrong. All other components of the suspension (controls arms, tie rods, swing arms, etc..) seem in really good shape from what i can see. I got some of the suspension components (tie rods and swing arms) replaced under the extended warranty 4 years ago and less than 45k miles ago. I am now wondering if this is not coming from the sway bar bushing. I will spend more time next weekend to try to identify where this sound is coming from.