95Viper made it sound much easier than it is. First of all, you will need something to suck out the old fluid, I got some pump thing for about $25 from Autozone, and it had a reservoir that repeatedly filled up, which was a pain in the ass, given the angle to pump out the stuff, then pour that into another container and repeat. Then you need to put the 4oz bottle in, followed by the main fluid. The 4oz bottle should be provided with a top piece that you can trim and then squeeze to get it in, but be aware that the entry to the differential is thick, so it is hard to get your fluid in properly. Regardless, you will need to pump the last half or so of the 4oz with the same thing you get to pump in the main fluid - again, a pain in the ass process.
Overall, what I'm going to do in the future and recommend to do is to get a differential drain plug installed (http://www.viperclub.org/menus/index_how_illup.htm) so at least only half the job is a pain in the ass.
Overall, what I'm going to do in the future and recommend to do is to get a differential drain plug installed (http://www.viperclub.org/menus/index_how_illup.htm) so at least only half the job is a pain in the ass.