Deleting large amount of data in ORACLE
If you want to be able to delete this data with the maximum efficiency, and you do not need to be able to roll the transaction back, then change the partitioning scheme to be based on days.

If you want to be able to optionally recover that data, then you could still partition it, but could remove it from the table using a partition exchange with a newly created table. You can then drop that table at a later date.

Re-partitioning aside, deleting 10 million rows is always going to require extensive undo logging, because a rollback operation has to recreate those rows. The redo would not be so extensive.

But it is never going to be a lightweight operation.

p.s. There's no such thing as blowing a transaction log, or putting a database down -- if you use informal, slang terminology to describe a problem then you're not describing it accurately, and you're inviting imprecise responses.