sys password change in dataguard

We have a need to change the sys user password in primary . and we have recently put a standby in place.

so what will be the recommended way to change the sys user password so that it wont break the physical standby .

on 11g doc it says
9.3.7 Refresh the Password File

If the REMOTE_LOGIN_PASSWORDFILE database initialization parameter is set to SHARED or EXCLUSIVE, the password file on a physical standby database must be replaced with a fresh copy from the primary database after granting or revoking administrative privileges or changing the password of a user with administrative privileges.

Failure to refresh the password file on the physical standby database MAY  cause authentication of redo transport sessions or connections as SYSDBA or SYSOPER to the physical standby database to fail.

however it says it may cause to fail which confuses me . appreciate any suggestion.

thanks
Kart

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