: Check the box for "Show historical versions of Minecraft: Java Edition in the Launcher".
: Historically, these were hosted directly on Mojang's servers. You can find direct download links for the 1.5.2 server and client jars via community-maintained lists like those on MCVersions.net or verified GitHub Gists . minecraft 1.5 2 jar file download
If you no longer have access to your old account, you need to purchase Minecraft again from minecraft.net. There is no legal “abandonware” exception for Minecraft versions. : Check the box for "Show historical versions