take the tca's out first from the inner bolts where they are on the crossmember

if you put the arb into both tcas while they aren't bolted to the crossmember all you need to do is tie the ratchet strap to either end of the tca (where the arb pokes through because its got grip there) and then pull in both sides at the same time

also, as you are putting the bolts through the inner tca get a deep socket and a long extension, you can then lever the bolt with the extension to get it to line up and then twat the end of the extension to drive it home
once it's gone throug just a little you can always screw it all the way through as the threads tend to bind on the crossmember

you need to leave everything thing just that little bit loose on the arb and the inner tcas because the car needs to settle onto the ground, so wheels on and move it back and forth a little to get everything seated properly before you get underneath and tighten the bolts up nigth and tight if you tighten them up before the cars on the deck you might find that you get funny squeaks or that the bushes get tensioned up in the air and then give you funy jiggles as you put them back on the ground