How can I delete support package

Dear all,

I would like to import a new support package: SAPKB70210 to solution manager, but I can't import as system still identify the last imported support package: SAPKD70257. I have try to find request in SE03 refer from: https://scn.sap.com/thread/1160748 but my request has already released. Could you advice if there and solution that can delete the SAPKB70210 not imported package and import again?

SE03, support package: SAPKB70210 has already released, not able to delete.

Rdgs,
Emily