In DSM Explorer, go to the following location: "/Domain/Software/Software Package Library/CA Software Packages/<My-Package>/Installations"
On the right side of the pane the installation jobs for this package appear, just like shown in the image:
Select (or multi select) the installation job records to remove, right click on them and select "Delete" in the floating context menu.
The following popup will appear. Press "Yes" to continue with the operation.
A new warning popup window appears informing us that doing so will not remove physically the installation but only the associated installation records in the database. Press "Yes" to confirm the deletion.
After that, the records corresponding to this package installation should have been removed.