SQL Server 2005 SP2 9.0.3054

Using the
EXEC sp_dropserver '<old>'
GO
and
EXEC sp_addserver '<new>', 'local'
GO
commands, I have successfully changed the host name
of a SQL Server box.

However, I notice that afterwards, under SQL Server logins,
I have 3 Windows groups that still contain the OLD host name.

<OLDHOSTNAME>\SQLServer2005MSFTEUser$<OLDHOSTNAME> $MSSQLSERVER
<OLDHOSTNAME>\SQLServer2005MSSQLUser$<OLDHOSTNAME> $MSSQLSERVER
<OLDHOSTNAME>\SQLServer2005SQLAgentUser$<OLDHOSTNA ME>$MSSQLSERVER

Is it safe, using Mgmt Studio, to simply rename <OLDHOSTNAME> to
<NEWHOSTNAME> in these groups? Will I break anything?

TIA

aj