Are you looking to get them swapped over to 3 prong for general use or are you looking to get them grounded for something specific? If you just want to plug 3 prong devices in you could look at installing gfi/gfci outlets. You’d need to investigate your lines but installation is pretty easy. If you need the outlets grounded for specific use I believe you can run a simple copper wire. Might require more looking into since I’m not super familiar with that one.
Are you looking to get them swapped over to 3 prong for general use or are you looking to get them grounded for something specific? If you just want to plug 3 prong devices in you could look at installing gfi/gfci outlets. You’d need to investigate your lines but installation is pretty easy. If you need the outlets grounded for specific use I believe you can run a simple copper wire. Might require more looking into since I’m not super familiar with that one.