Is removing unwanted extensions possible?

In my case, it's a direct install from the LibreOffice site and maybe that's why I find the extensions folder at /etc/libreoffice3.5/share/extensions. I'll try first with a dictionary.

@luyu, your answer works for me but please edit it to include the possibility that the extensions maybe found as I indicated in the previous comment, at least for some users.

Actually you shouldn't just delete these files but use package manager (Software center or Synaptic) instead to remove these. If this is not possible (they come in bundles or are dependencies for something you really need), you could just disable these from Extension Manager. Few KBs don't hurt.

@mahfiaz The question refers to bundled extensions that cannot be removed using either package manager or LibreOffice Extension Manager. If backup and not removal is done as suggested in the answer, extensions can be restored if needed. As for disabling them, lock might prevent this too.