You don't have to drop the exhaust. I took so heavy duty zip ties and forced them to pull up on the down pipe from the bracket the connects the cross braces on the firewall.
I wouldn't bother it'll drain itself
The turbo cooling line clamps (the little ones I assume) are one use only. I would strongly consider buying all new lines so yours won't leak. Also you will need to replace (likely) the crossover cooling hose underneath the turbos. It's a small hose with a plastic T in it. It will be broken now or will break when you touch it. Get the BMW brand the Rein brand will break again after a year. (Bummer). Now is also the time to replace the turbo oil cover it will be leaking oil if it's never been changed. BMW part $75 or so.
If your CCV lines are intact I would not replace them. They are easy enough to get to later. There is a round ring you can squeeze to pull them apart. The other end you have to work carefully with a flat blade screw driver.
Note you will need E-torx, regular torx and hex head sockets to get all this done.