If you want to place the files in the existing directory, then ensure that the directory is empty. If you want to place the files into a different directory (and remove the previous files), ensure that you update the environment variable setting to reflect the new location.
Note:
A restriction on Instant Client or Instant Client Light is that you cannot perform patch upgrades using the opatch utility because the Instant Client installation does not create an inventory, which the patch upgrade process must access for patch upgrades.