1. The best way is to run sp_removedbreplication.

2. After you run sp_removedbreplication, you may run the following
script in your restored database. This script will generate the drop
commands for replication related system tables, views, stored procedures
and triggers. You may check the generated output first to make sure it
does not drop your own user object, and then run the output to drop
these information.

set nocount on
Select 'drop table ' + name from sysobjects
where name like '%conflict%' and type='u'

Select 'drop table ' + name from sysobjects
where name like 'MSMerge%' and type='u'

Select 'drop trigger ' + name from sysobjects
where type = 'tr' and status < 0 and category = 2

Select 'drop proc ' + name from sysobjects
where name like 'sp_%' and type ='p' and category = 2

Select 'drop proc ' + name from sysobjects
where name like 'sel_%' and type ='p' and category = 2

Select 'drop view ' + name from sysobjects
where name like 'tsvw%' and type ='v' and category = 2
Select 'drop view ' + name from sysobjects
where name like 'ctsv%' and type ='v' and category = 2

3. (optional step) you may use the steps in the following article to
make sure your user objects are no longer marked as being used in
replication (by change the replinfo column of the sysobjects to 0. This
steps is only needed if the replinfo column is not 0):

http://support.microsoft.com?id=326352

4. (optional step) check the steps in the following article to make sure
no columns are being marked as replicated:

http://support.microsoft.com?id=811899