Dropping old partitions on a 1 TB data warehouse partitioned table

We have a data warehouse table that is 1 terabyte. A script was originally written to trim the older partitions (home-made primary key, not date based), keeping just the last 365 days. However this script has not been run since June of 2023. There are 7 global indexes on this monster (don't blame me, I inherited this just a few months ago), and we are looking at removing all the partitions which have created date > 365.

Any suggestions as to getting rid of the old partitions gracefully without losing half my life in the process?

We are on 19.24.

Additionally, ALL of these indexes are used, based on dba_index usage.