1) Remove all power to the laptop.
Unplug the AC adapter (Charger) and remove the Battery.
2) I suggest you wear an ESD wrist strap. Connect the alligator clip of the ESD wrist strap to a good Ground source.
(I connect the clip to the metal frame of an empty desktop computer case)
This is an example of an ESD wrist strap,
(Electro Static Discharge)http://www.hotdealshop.com/html/productOverviewNew.aspx?prdId=23733FR030910
You can see the price of this one is under $4.
Perhaps some 'Mom and Pop' computer repair shop will have one.
Reasoning for ESD wrist strap;
Your body carries Static electricity.
Static will fry out (Short Circuit) the hardware components inside a computer.
(Some examples: Processor, Harddrive, Ram Memory, Graphics Card, or GPU, etc.)
The ESD wrist strap will relieve your body of Static.
(If a person's budget will not allow this expenditure, you could fashion a homemade version)
3) There may be as many as 60 plus screws, and 10 different types. Do Not mix them up!
Some of the screws look to be the same size, and have the same thread. Nope!
Use a multi-compartment container for the various screws you will remove. Label each compartment, for the area of the laptop that you removed the screw from.
You can use a clean egg carton in a pinch, and label each egg holder.
(I work on laptops, and use them anyway. Saves on cost)
4) Laptops are disassembled from the top going down. There is no removing just the bottom cover.
If you are going to completely disassemble the laptop, the LCD display assembly will be removed first.
Then the Keyboard/Hinge Cover. (Plastic strip above the Keyboard, and below the LCD screen)
Next Keyboard, static Shield Cover, and then you can access the internal hardware parts.
(Processor Heatsink Assembly, Processor, and so on)
A) Service Manual (Free)http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-sony
Under the heading Sony, go down to the bottom row.
Begins with VGN-A
Go to the right, and left-click on VGN-B
(The Sony VAIO VGN-B100b is one of the VGN-B series)
This is a PDF file. Give it a few seconds, and it will download.
(Watch the download progress bar, let the file download all the wat before looking through it.
The computer you are using has Adobe Reader on it. Adobe Reader uses PDF files.
The file will automatically download, and open.
If you do not have the latest version of Adobe Reader, suggest you upgrade. Adobe Reader 9.3.4. )
The above free Service Manual has photos, and instructions.
Not as concise, and clear as I myself, would like, but you may find it to be a useful resource.
You can save it to your computer, and burn a copy off to CD disk.
This link also has photos, and instructions, but is for the Sony VAIO VGN-BX.
It's a step by step, with clear photos. You can left-click on each photo to enlarge them.http://www.insidemylaptop.com/disassemble-sony-vaio-vgn-bx-series-laptop/
Should this be your first time disassembling a laptop, or a VAIO VGNB100b, you may find the above useful.