Going from leap 15.4 to 15.6

Hi, I know not to skip versions when upgrading, but that's not quite my question. A while back I got one of the mini-pcs measuring about 10cm X 10cm X 4cm. Installed 15.4 on it..smooth, but didn't use the installation beyond setting an account up. I want to go to 15.6, and I know not to try to go from 15.4 directly to 15.6. So, how should I proceed? Use gpartd to delete the 15.4 installation? If so, how should I deal with the UEFI stuff? (and the UEFI stuff is really my big question here) Thanks for any tips. Mark -- Jumping to conclusions can be bad for your health.