You would have to change the folder ID if you want to move a bookmark. To remove a bookmark there are two main tables moz_bookmarks and moz_places and possible links to moz_keywords and tables that deal with annotations (moz_annos, moz_anno_attributes) and moz_favicons. You can see that this can require a lot of work if you want to do this properly. Some files that have SQL statements that deal with bookmarks. https://dxr.mozilla.org/mozilla-release/source/toolkit/components/places/Bookmarks.jsm https://dxr.mozilla.org/mozilla-release/source/toolkit/components/places/Database.cpp https://dxr.mozilla.org/mozilla-release/source/toolkit/components/places/PlacesDBUtils.jsm https://dxr.mozilla.org/mozilla-release/source/toolkit/components/places/nsNavBookmarks.cpp Maybe try to ask at the Reddit forum. *https://www.reddit.com/r/firefox/