TTH shows up as an additional button in your ToolBar:
Before starting using TTH, you will need to have a proper UFO file with Quadratic (TrueType) outlines.
For that you may use the QuadraticConverter.py extension that will create a new Quadratic UFO from a Cubic (PostScript outlines) file. Also available through Mechanic.
Make sure that your UFO can generate without error into a .ttf font because TTH will use a temporary .ttf file to preview outlines and bitmaps.
Once TTH activated the the main window pops up:
It is from there that you will be able to select and set up the hinting tools.
Click on the gear button and this menu will appear:
• ‘Monochrome’, ‘Grayscale’, and ‘Subpixel’ define the rasterizer preview.
• ‘Preview’, ‘Program’ and ‘Assembly’ are additional windows.
• ‘Control Values’ is a sheet where you must set up parameters of your font such as CVT stems, alignment zones, etc.