Plug-ins

Ok, this is really noobish, but can someone tell me how to use downloaded plugins in Blender

sequence or texture?
sequence: http://wiki.blender.org/index.php/Manual/Sequence_Plugins
texture: http://wiki.blender.org/index.php/Manual/Texture_Plugins

actually I wanted to use downloaded python script plug-ins from

http://www.blender.org/download/python-scripts/wizards/

oic http://wiki.blender.org/index.php/Manual/Extending_Blender