If u can get the drain plug out and back in with out losing it all then yes you can just drain some. Other option is drain into a clean container then just use that to refill the bike back up to where it should be.
07 vstar 650 midnight custom
Ais disable, 4.5 inch risers, V&H cruzers, jetted with pods, viking saddlebags, Kuryakyn mini boards and memphis fats windshield, fuel solenoids deleted, star solo seat and 4 inch extensions. Boss audio sound system.