1. Install Stylish and restart Firefox when prompted.
   • https://addons.mozilla.org/firefox/addon/stylish/
2. Click the ≡ Menu Button and choose Add-ons.
3. In the Add-ons Manager, click User Styles on the left.
4. Click the Write New Style button at the top. Paste the following in the text box, give the style a name, then click the Save button.

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

#PanelUI-fxa-status { display: none !important }

If you don't want to install an add-on, you can use the userChrome.css file instead, but I don't recommend it.

• http://kb.mozillazine.org/UserChrome.css

If you use userChrome.css then you need to create and chrome folder and the userChrome.css within this folder.

• Create the chrome folder (lowercase) in the <xxxxxxxx>.default profile folder if this folder doesn't exist
• Use a plain text editor like Notepad to create a (new) userChrome.css file in this folder (the names are case sensitive)
• Paste the code in the userChrome.css file in the editor window and make sure that the userChrome.css file starts with the default @namespace line

• http://kb.mozillazine.org/Editing_configuration

See also:

• http://mxr.mozilla.org/mozilla-release/source/browser/components/customizableui/content/panelUI.inc.xul

Already had Stylish installed, but this Write New Style button at the top is nowhere to be found. Does the operating system matter for this functionality to work ? I'm running FF on Linux Mint XFCE.

P.S. Can't I do this through about:config ? Looking at:

identity.fxaccounts
services.sync.fxa

NoLogo wrote:

Already had Stylish installed, but this Write New Style button at the top is nowhere to be found.

It shouldn't make a difference what operating system you're using. In any case, you can click the Stylish toolbar icon and choose Write New Style, then Blank Style.

NoLogo wrote:

P.S. Can't I do this through about:config ?

Not that I can see.

Because I had a feeling there was something else wrong, I started by re-installing Stylish. After repeating this three times, the Stylish button appeared in my add-ons menu and on the FF toolbar. My guess: the old Stylish installation had become corrupted. Why it took three re-installs I don't know. Perhaps it uses an un-install script it generates at installation ?

After this I generated the Stylish script which successfully removed the Sync button from the FF Start menu. I'm happy.

So the old saying that applied here: If you don't succeed at first, try again.

Thank you for your help, both of you.