You may be able to access the bearings by just carefully removing the seals with a thin flat blade of your choice. You can then flush them out and add fresh lube and can be done on the bike but removing the BB makes it easier. I'm not sure what the recommended type of lube should be used as full ceramics require something other than the usual grease but it looks like yours are "hybrid" meaning steel races with ceramic balls and grease may or may not be OK. Check out some ceramic bearing sellers for info on lube.