To save money I will be doing my own drive service this year. I have Bravo 1 drives that are attached to 350 mags. I was wondering if there are any tips that any of you may have. I have watched a bunch of you tube clips, it looks straight forward. I do have a question though. In the engine compartment, I have a drive lube bottle for each drive. What is the best way to drain that fluid, will it drain out the drain plug on the drive if given enough time? Or is it best to clamp off the line and save it. If I do drain the bottles, do I pump in enough fluid to fill them from the bottom of the drive?

It will drain out of the bottles unless you clamp off the hose. I always let all mine drain out. Remove the caps on the bottles.
When I refill from the bottom, I pump in enough lube to just get some to start filling the reservoir bottles, then I top them off from the top.