You can just put some grease on the lip of the bellows.
Make sure you replace the o-rings on all the oil plugs. There are 3 of them including the dipstick.
When I drain my Bravo 3 drive, the lube bottle also drains at the same time.
When I fill, I fill from the bottom until it reaches the vent. Install drain and vent plugs and then fill the gear oil bottle.