If you have installed a font and you want to replace it or remove it from your phone, follow these simple Steps:
First, Go to C:\System\Fonts using X-plore(see Downloads section) or any third party file manager like BlueFTP, FExplorer etc.
Next, rename the "Fonts" folder to
any name you want, for example: Font
You may now delete the renamed "Fonts" folder
Lastly, restart your device.