Need help to open an external disc drive

[Fedeweb]

Hi everybody, this is my first post here, I'm writing from Italy (so sorry for my bad English).
I've change a lot of belt on my CPC (I've 5 amstrad in my collection) with no problems. Now I have to change the belt on an external disc drive made by Schneider. I've take out all 4 screws but I cannot remove the cover to open the drive, it seems to be blocked near the back side. Someone could help me?
It is a stupid question, but I don't want to risk to broke the drive drive.
Thanks to everybody!

If you are interested, I've make a "special" with a lot of pics on my website to change the belt on the CPC and I can leave you the URL.

[Fedeweb]

I've find the others screws covered by stickers!!
Sorry for the stupid post!! 

[Cholo]

No worries, dont be afraid to ask again if you get into troubles 

[Gryzor]

Hahaha I knew it was that even before I read your second post - I've had this happening to me a few times with different machines

PS Oh, and welcome

[Doktor]

Hi everybody, this is my first post here, I'm writing from Italy (so sorry for my bad English).

Hello and welcome,

we are allmost neighbours, as I live in Croatia...