How to delete index on odbc-linked database?

Hello!

I have a really weird problem, here:

I'll have to link tables of a sql server 2005 database to an access
2003 database.
This works without a problem, but those linked tables get up to five
(!) primary keys -
NONE of them is defined as a primary key in the server database.

I tried anything I could think of in DAO and ADO, to delete those keys
- without any success.
Has somebody ever done this and knows how it is possible?

Any help is appreciated!

Thanks a bunch,

Carl