I changed my FARB on my 147 about 3 years ago and it required the complete removal of the sub frame. I needed two jacks to push everything up back up to fasten it up. I'll try to find the p;osts that guided me for you!
Putting it back - it is easy to get the 13 mm bolts at the back in. Start with those, and the thing is roughly in place. Then get the "horns" in - this is where a bit of shoving is needed with the jack. Once those are in the rest is easy. Torque - for the bigger bolts, just yard on it with a sensible sized ratchet
Get all the bolts in loosely before tightening any of them, and get the alignment checked afterwards.
Some of the bolts (particularly steering rack) are VERY tight (or at least they were on mine). You'll need good sockets and a securely raised car and as said above two trolley jacks help a lot. Its not too bad a job but can depend on how many problems you hit. It just takes one or two problem bolts (eg on exhaust) to slow it down.