Copy 2 databases without detach in SQL 2005

I have a server with live databases, and I have a test-server where I sometimes restore databases from the live one, to get fresh data. But this way I have to set up all the users again, I have about 4 different users with different permissions that need set again.

Is there some way to do this a better way without using detach and attach, since I cant take the databases offline on the live-server?

Prefered some thing I could run that "re-fills" the tables with fresh data. No need to redo stored procedures and rights.

Note that 开发者_JAVA技巧I cant use some generate scripts. The databases are too large for that.

/M

Backup - restore is what we are using. To copy users with exact SIDs and passwords search net for sp_help_revlogin script - this way all permissions are kept intact.