Care must be taken when following these instructions, as it is possible to destroy your router and turn it into a round cornered brick. You have been warned.
Do not attempt to flash the router using a wireless connection to the computer. This will almost certainly brick the router. Use only a wired Ethernet connection.
There are several different methods of flashing a router and which one is used depends on the router model. Different manufacturers use different methods of upgrading their routers and, in many, cases, a special method must be used to flash to ROOter.
In order to cover all possibilities, a readme.pdf document is included in every image archive that explains the different methods. Also included is a text file that will tell which method to use and any special instructions that may be needed. In this manner the methods used to flash routers is kept up to date.