My car is lowered and I can swap mine in 5mins without jacking it up. But I'm not exactly fat so I can fit under easily :P Its a 3/4" nut, which is something like 19 or 20mm in the normal system, but since it is torqued up so high (140Nm) you might need a breaker bar as well as another 3/4" spanner/socket to go over the bolt to stop it from spinning. 1) I'm fat and could still fit under the unjacked car! I chocked the front wheels though, and used that boot jack to support the middle-rear support just for safety. All weight removed from boot. 2) Took waaaaay longer than 5 minutes, though I think in future it could be done. I had some difficulty aligning the holes etc. 3) A 19mm is perfect, breaker bar wasn't really needed (me strrrrrong), and a wrench was needed to hold the bolt from spinning. A ratchet was helpful/ 4) What are those wires/cables attached next to the nuts? Their brackets kept getting in the way... All done! Thanks guys! Sarah bought me a new ratchet/socket set for my efforts (that's love for you)- but I'm ashamed to say its the HSV brand (but it comes with a lifetime warrantee, and was a good price).