sp_changedistributor_password (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Managed Instance
Changes the password for a Distributor. This stored procedure is executed at the Distributor on any database. If this is a remote Distributor, then it needs to be run on all the Publisher servers that are using this Distributor. If the distribution or Publisher database is in an availability group, then it needs to be run on all the Distributor and Publisher nodes. It doesn't matter if the node is primary or secondary.
Transact-SQL syntax conventions
Syntax
sp_changedistributor_password [ @password = ] N'password'
[ ; ]
Arguments
[ @password = ] N'password'
The new password. @password is sysname, with no default. If the Distributor is local, the password of the distributor_admin system login is changed.
Return code values
0 (success) or 1 (failure).
Remarks
sp_changedistributor_password is used in all types of replication.
Examples
-- Change the password on the Distributor.
-- To avoid storing the password in the script file, the value is passed
-- into SQLCMD as a scripting variable. For information about how to use
-- scripting variables on the command line and in SQL Server Management
-- Studio, see the "Executing Replication Scripts" section in the topic
-- "Programming Replication Using System Stored Procedures".
USE master;
GO
DECLARE @password NVARCHAR(50) = "YourLongP@$$w0rdHere";
EXEC sp_changedistributor_password @password;
GO
Permissions
Only members of the sysadmin fixed server role can execute sp_changedistributor_password.