1) Remove ALL power.
Remove the AC adapter (Charger) and Battery.
2) Lay a static free cloth on the table, or workbench you are working on.
(Protects the table, and the laptop)
Laptop closed turn it over, set it down on the static free cloth, Bottom side up.
3) Locate the HarDDrive Compartment Cover.
(Sony's term is HDD Slot Cover)
Looking at the bottom of the laptop, this is the rectangular cover that sits vertical, at the Bottom/Middle of the laptop.
The DVD optical drive is to the Right.
Remove the two Philips head screws which hold the cover.
Remove the cover.
(It has tabs made out of the plastic cover, which are on the opposite side of the screws. These tabs slide down into the Bottom Cover of the laptop.
When removing the cover use care, and do not break these tabs off)
4) With the harddrive compartment cover removed, look at the Right side. There is a square depression next to the right edge, in the middle.
(The square may be colored Blue)
There is one single Philips head screw to remove.
Then the DVD optical drive tray is opened by pushing it's release button.
The tray is used to gently pull the DVD optical drive out of the laptop.
This is a link to a free Service Manual,http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-toshiba
Go down to the 'paragraph' that starts with - Satellite A10. (A10 in blue)
Drop down to the 5th line. (Begins with M500 in blue)
Scroll across, and click on P500.
This is a PDF file. The computer you are using now has Adobe Reader on it, which uses PDF files.
After you click on the file name (P500) it may take up to 30 seconds, before the first page comes up.
At the top of the PDF file is the page number box. It is to the Right of the Down Arrow. Go to Page 188.
Or use the Bookmarks menu to the left.
Left-click on the + sign next to -
Chapter 4 - Replacement Procedures.
Then scroll down, and left-click on -
4.5 Optical disk drive
(The Adobe PDF file may be in a different format, when it comes up.
Hover your mouse cursor towards the Bottom/Middle.
In the bar that appears go to the far right, and click on the red Adobe PDF icon )
For additional questions please post in a Comment.