How to switch External Data Source?

i AM STUCK in Metastock external data source and want to get back to TC2000 external data source.
Looking at the very bottom of page 1 of How to use Amibroker with external data source the last part of the bottom line says to DISABLE the Local lData Source related to the Metastock plug in in order to make this switch.
I can not find how to perform the Disable from the local Data Source. I have looked at various control / setup pages and can not find this disable.
What am I doing wrong - or looking in the wrong place

@jcs: Are you creating a NEW database? That may be the simplest way..

Thats for the idea but i have try that if I can get our of this stuck more.

Have you tried changing the Data Source?
File > Database settings > Data source > Data source:
Open the list box and select the TC200x/TCNet Plug-in.
In Local data storage select the Enable radio button. That might break the MetaStock db link.

I agree with snoopy.pa30 that creating a new database ( File > New > Database) is the best method. Be sure to check the box "Load this database at startup" and it should open the new db rather than the old MetaStock db.