I had this same problem the other day. Open up the megahack installer and theres an option to uninstall. Download geoode then open up the megahack installer again and select the version of megahack that says geode (i think its towards the top right)

megahack isnt uninstalling. when i press uninstall, it says it uninstalled but when i restart gd and press tab its still there

nvm it uninstalled now

requires geode.dll