Dear micimoco,
Sorry ..not to be in sync with you again..Iam giving the referrence link of service manual of SONY VAIO PCG-FRV series ,for what you are looking for.
http://www.eserviceinfo.com/downloadsm/23149/Sony_Vaio%20PCG-FR%20&%20PCG-FRV%20Series.html
In the page 10 of manual.the exploded diagram of mother board and related SI parts .The screws responsible for the fixing of the optical drive clearly mentioned there ,You can have a look at it.
For the replacement instructions you can refer the below site..
http://www.bixnet.com/sovapcsehadr.html
I hope I have reached your expectation by this time. For any clarication again don't hesitate to contact me .
Regards
Yathisekhar
Edited by Yathi on December 8 2006 at 9:50 PM