If you already have an older version installed, open Adobe UXP Developer Tool, find the existing shikomi.ai plugin, and click Unload.
In UXP Developer Tool, click Add Plugin and select the newly downloaded .ccx file.
Reopen Premiere Pro — the shikomi.ai panel will use the new version.
Older version (rollback)
Only use this if the latest version is broken for you. Once installed via UXP, it talks to the same server as the latest version — no other change required.