A real pain since the ARB are fitted with the mounts spot welded to the subframes. You can't buy just a bush, but if you search the Multipla forum (same suspension setup) you can find many DIY options for replacing them.
Found my old post from 24.01.2012, good timing I guess.
"No need to drop the subframe, it has holes so you can access the 13mm bolts holding the brackets. I undid them on both sides and slid the bar to the sides as much I got it to gain easier access and split the brackets. I also filed the guides on the upper bracket to more cone shape so it just bolted right back in (youll understand once you have the thing split). ARB stays in the car."
Just used a solid flathead and hammer to initially split it.
Image. I ended up reusing the old ones (cut the slit open and put some rubber mat over it to compress the bush when bolted together.
Theyre really not welded together, more like pressed and flanged (see the filing bit on post above and in the image you can see the shiny bits on the upper clamp).
The new bush you see on the pic is for Multipla, they can be bought (not from fiat)
So the ARB bracket isn't also spot welded in addition to the 13mm bolt? It is mentioned on the multipla forum that you have to crack the spot with a chisel.
As for ARB - if you hover over the word it gives you a definition.
No weld marks on mine and why would bolton part be spotwelded to thick steel subframe, would need some current as its not thin sheetmetal. Chisel could also be used to separate the halves.