Hi Guys,
I have two questions regarding replication:
1, If I don't continue to use replication at all, how can I drop replication
completely? Because too many command, e.g. sp_removedbreplication or
sp_dropplication and so on. Which one can I use?
2. If I want to retore the replication database and want to keep replication
so that I can continue to use replication, do I need to setup some steps
before restore database?
Thanks.

To remove replication, use sp_removedbreplication. There might be a few
orphaned objects left behind but these can be deleted by hand or simply left
there as they won't cause any problems.
To restore a replicated database, pls have a look in BOL for the topic
"replication, backup and restore operations".
Cheers,
Paul Ibison SQL Server MVP, www.replicationanswers.com .