I tried the second way, downloaded kmod-29-4-...x86_64.rpm and ran zypper install kmod... .rpm. However, this does not seem to be the good way, because it reports a conflict with 'libkmod2 < 29-4'... and if I wish to go on it would uninstall about 100 components. So I guess a more complex update is required. However, I don't know how to proceed, having no wifi, just the option to plug-in a USB stick.