Use drop subscription to delete a database subscription.
drop subscription sub_1a for database replication definition rep_1 with primary at PDS.pdb with replicate at RDS.rdb
without purge ...
Dropping a database subscription does not affect existing table or function subscriptions. Similarly, dropping a table or function subscription does not affect existing database subscriptions. However, in this case, the replicate tables may need to be rematerialized.
See the Replication Server Reference Manual for complete syntax and usage information.