Home /Packages /Feature Manager »Edit Feature List
there should be an option to uncheck toolkit.
but not sure if your just looking to remove the link or WordPress toolkit all together ?
I've not tested if it just removes the link or total WordPress if you have WordPress installed ?
Editing the feature list would remove it from the cPanel interface for customers that have a package with that feature list. Uninstalling the software would remove it for all users on the system.