The Acer Aspire 9303, is part of the Acer Aspire 9300 series of Notebook PC's.
I have good news, and not so good news.
This is a link to free Service Manual,http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-acer
Drop down to the 'paragraph' that starts with Aspire 1200. (1200 in Blue)
Go down to the 13th line (8390Q), scroll across, left-click on 9300.
[ Ignore the following if you are aware;
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 (9300), it may take up to 30 seconds to download.
After the file has downloaded, bring your mouse to the bottom of the page.
The 'ghosted out' Navigation bar will appear.
Go all the way to the right, and click on the Adobe PDF icon.
(Looks like a three pointed 'star' ]
Start on Page 69. (PDF file page number at top)
Direct information for removing the Fan Assembly, is on Page 78.
Not so good news:
The Display Assembly has to be removed, and the laptop disassembled down to the motherboard removed, to access removing the Fan Assembly.
1) Remove ALL Power. Remove the AC adapter (Charger), and Battery.
2) Advise use an ESD wrist strap, and connect it's alligator clip to a good ground source.
Average cost is around $3 to $6. Cheap insurance, so you do not Static shock, the delicate hardware components inside your computer.
Do not wear one, and have it connected to a good ground source, and you can use the laptop for a doorstop.
3) Use a multi-compartment container, for the various screws you will remove. Label each compartment for the area the screw/s come out of.
SOME screws look VERY similar to other screws. Advise Do Not mix them up.
4) If this is your first time, make a record as you disassemble. Make notes, and drawings, and/or use a digital, or video camera. Use good lighting, and make legible notes.
Nice to have a Service Manual, but even nicer to have your own personal record to refer back to, in case you are interrupted.
For additional questions please post in a Comment.