upgrade to v7r1 ii14482 recommend to delete USER_STG files

Preparing v6r1m1 to V7r1 on a partition.
Info Apar ii14482 says:
<clip>
The following database PTFs are needed to avoid a database
cross reference file error condition during the upgrade to 7.1:

If you are upgrading from V6R1Mx - SI45174
SI47823
SI47825


If these ptfs are not applied to the previous release prior to
the upgrade, a RCLSTG SELECT(*DBXREF) may be required following
the install of the operating system in order to successfully
install several products that are dependent on the data in the
cross reference files.

For V6R1Mx you also need to take the
following actions AFTER you have applied
ptfs (application of database PTFs can
recreate these views):
*
DLTF QSYS2/USER_STG
DLTF SYSIBMADM/USER_STG
*
Failure to do so, will result in having
to run RCLSTG SELECT(*DBXREF) to
repopulate cross reference column level
information following the upgrade to
7.1.
</clip>

So when exactly do I delete the 2 files - while on 6.1, after the ptfs
applied (they already are).?
I just don't understand the phrase:
For V6R1Mx you also need to take the
following actions AFTER you have applied
ptfs (application of database PTFs can
recreate these views):
These ptfs were applied weeks ago, but Operations, but no file deletions.

Jim Franz