Remove the front clear cover, with a very-very-small “watchmaker” screwdriver.
Take the unit with the 2 instrumentations and its scales, out of the case.
For setting the temperatur and humidity, turn the instrumentation covers at the back. This is easy-going! Don´t try to use a screwdriver to turn the 2 screws!
Repeat (3) several times.Don´t expect magic or exact measurement .