Absolutely you can do one side at a time, no problem. And being as the u-joint would be so much easier to change at that time, I'd probably change it then too. If you do, I recommend the Spicer 5-760x u-joint which looks like the Spicer 297 that is in there now but it's a nice inexpensive upgrade. The 5-760x is more rugged and longer lasting. Moog is a good brand for the ball joints.