• Disable Flashblock using the Options in the Extensions window.
  Tools->Extensions->Flashblock->Options
• Uninstall Flashblock from the Extensions window.
  Tools->Extensions->Flashblock->Unistall
• Shutdown Firefox.
• Delete, rename, or edit the userContent.css file in your profile/chrome directory to remove all references to Flashblock. Our F.A.Q. has several useful links on how to locate the location of your profile directory.

  Or, you can install ChromeEdit  http://cdn.mozdev.org/ instead and use it to find and edit your userContent.css file without having to search all over for it.

• Restart Firefox twice to complete the removal.

1. Go to the Mnenhy extension website http://mnenhy.mozdev.org/.
   • Install the Chrome Manager module from the Mnenhy extension http://mnenhy.mozdev.org/installation.html.
   • Use the Chrome Manager to remove the Flashblock extension.
     Tools->Chrome Manager...->Packages
     Highlight the flashblock entry and press the DELete key, or right-click on the entry and select Remove.

     The Chrome Manager page has some useful information on it's usage http://mnenhy.mozdev.org/chroman.html.

2. Go to https://addons.mozilla.org/.
   • Install Jeremy Gillick's Extension Manager from https://addons.mozilla.org/extensions/moreinfo.php?id=203.
   • Use the Extension Manager from the Tools menu to uninstall Flashblock.

1. Shutdown your browser
2. Delete, rename, or edit the userContent.css file in your profile/chrome directory to remove all references to Flashblock (This step is not needed for SeaMonkey).

   You can install ChromeEdit  http://cdn.mozdev.org/ and use it to find and edit your userContent.css file without having to search all over for it.

3. Restart your browser to complete the removal

1. In the K-Meleon/chrome-folder, delete the flashblock.jar file.
2. In the installed-chrome.txt file, delete this row:

   content,install,url,jar:resource:/chrome/flashblock.jar!/content/flashblock/

3. In K-Meleon Edit/Preferences/Settings go to the tab userContent.css and delete the following lines (or similar):

   object[classid$=":D27CDB6E-AE6D-11cf-96B8-444553540000"],
   object[codebase*="swflash.cab"]
   { -moz-binding: url("chrome://flashblock/content/flash.xml#obj"); }

http://kb.mozillazine.org/Uninstalling_extensions
http://kb.mozillazine.org/Firefox_:_FAQs_:_Uninstall_Extensions#Uninstalling_manually

Then edit the userContent.css file in your profile/chrome directory to remove all references to Flashblock.