I don't remember the exact fitting method but I know they don't come with the brackets. You drill out the upper mount of the factory strut and the new one screws in through that hole.
We have some polo shirts left from our last order so I thought I'd post up the available sizes for anyone who is interested. Prices are $25 each.
11 x L
17 x XL
3 x 2XL
This is what they look like for those that haven't seen them: