You can press out the old bearing cartridges from the BB shells and find the bearing numbers that you can match up from most bearing suppliers. It is a bit of a PITA and you need some tools that will work for this such as a bearing puller, or some bolt sockets of the right size that can be used to remove and install the bearings or possibly some auto supply stores may loan out the bearing tools. To make it a little easier put the BB in the freezer for at least a couple hours, have your tools and some boiling water ready when you take them out of the freezer and work fast by pouring the hot water over the aluminum shell of the BB trying as much as possible to keep it away from the bearing and start trying to get the bearing out. This helps to make it a little easier to remove the bearing. You may only save half of what a new BB would cost plus the extra time needed searching for the correct cartridge bearings and removal/replace time so something to consider. There is also this place that sells the DIY bearing kit but only a few $ less than a full BB and not sure what the quality of their bearings are.
https://www.enduroforkseals.com/prod...OBKGXPCSB.html