How to delete files from Integration staging area?

Summary

Delete files from Integration staging area/local file system, that were downloaded from FTP adapter

Content

I have downloaded some 1000 files using FTP adapter in the integration local file directory (/tmp/instance_id) folder.

I have identified some files that I no longer need from these downloaded files. 

How do I delete those files from this local file directory? Once those files are deleted, I can simply zip the entire directory (i.e. /tmp/instance_id) and write it back to the remote FTP server location.

Version

21.2.3.0.0