Remove the *entire* instructables header, NOT just graphics
You need greasemonkey and, optionally for firefox, the stylish addon.
Install and enable the following scripts:
Please note, you will need to either stay logged in all the time (so keep cookies on!) or else disable these scripts to be able to login, use the forums, and upload new instructables and the like, unless you type the urls directly - laborious!
Please let me know of any bugs.