Databases are just files. You just need to move  the .dbf files.

These instructions would be for MS SQL 2005. Not much different than
2000. If you are looking to make room on the C drive, this would be the
way to do it without having to beg sharepoint  to come back to life
after. Just move the dbf files  and remount them on the Same sql server.
The database  server its self doesn't take up much space  and can stay on
the c drive. Here are some steps to help  you get that done.





Step one. Shut down SharePoint

Step two. Open Enterprise Manager

Step three. Find your Servername_Config Database.

Step four right click-tasks --detach (make sure you know where the .dbf
files live )

Step five. Repeat for other databases relating to Sharpoint. I think
four database, maybe five if you have a lot of things going on. Some
will start with sharepoint, some with WSS and others will start with
Shared services.

Step six. Copy files from folder. Example of where to look:
E:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data

Step Seven. Paste to new partition

Step Eight. In SQL, Right click on the tree where it says Databases.
Select Attach.

Step Nine. Attach the dbf files to from new partition. Repeat for all
dbf files that you moved.

Step ten. Turn on Sharepoint and you will be good  to go

I would agree with most of this. However SQL database  files are MDF
files (with the transaction logs being LDF files), not DBF files.
Second, I would back them up, detach them, then restore your backups to
their new location. You can get into trouble moving the MDF and LDF
files in the file system, so backups are a better course of action.

http://support.microsoft.com/kb/224071/en-us
How to move  SQL Server databases to a new location by using Detach and
Attach functions in SQL Server

"Detach and Attach" or "Backup and Restore" ? Actually both way will
work. I tried the Detach and Attach before. It works fine and I prefer
this way because it is faster.

To make it safe, you can always backup the database  first before
detach.

Anyway, the choice is on you. Both way will work.