Update SLE 12SP4 a SLE15 on AWS

Good night friends. Please, does anyone know what the process is to upgrade an SLE 12 SP4 to SLE15, I have it in aws and I can’t find any help manual.

Also, I have another server with SLE 12 SP3 and when I run the zypper plugin to migrate it does not find the update for SP4. Does anyone know if in aws how would the process be for both cases please ???