Guide to Run Old & Incompatible Add-ons on Firefox 4

Mozilla has launched the latest iteration of their web browser, Firefox 4. We all know that Firefox 4 brings lot of much needed features to the table, but what if your old Firefox add-ons doesn't work with Firefox 4? To solve your problem here is a small guide to run old & incompatible add-ons with Firefox 4. There are two different methods to solve this issue. The first and the simple one