Did mine recently, you get One Shot, Landrover make it, it comes in a ready measured bottle with a nib or sachet.
Drain the old stuff, with your wheel at full lock blast in the one shot. To get it to flow in better put it into a bath of boiling water for a while, I also found a small piece of tube pressed over the nib (I have the bottles) and then you can put that right into the swivel. Easy enough job.
Once its in its in, but I would top it up with a little oil.
If you have trouble getting the grease let me know.