When i have done this for people in the past I locate the make and model, and then get a hinge of ebay. There are usually people selling bits like that of broken laptops they have stripped. I would search in ebay something like "Toshiba L300D Laptop hinge" using your make and model ofcourse.
They are really not that hard to replace normaly as long as you are patient and take your time and be very careful. I normaly check this site
and usually find the model or simular model I want to strip down or replace a component etc, the instructions are very good. Also you could do a search on google for the service manual for your laptop,sometimes these are easy to find, and sometimes not. Also do some searches for things like for example "Toshiba L300D disassembly" etc, and as well as the google web search, try selecting google video search.
Good Luck rondo341,