Let me bust out the 4" thick shop manual I bought
. This is for a 2008-2011 Mk2 though but maybe it will be the same?
Right behind the glove box (folds down)
1. lower the glove compartment
2. disconnect the blower motor resistor electrical connector
3. detach and remove the blower motor resistor. Remove it from the housing by sliding the resistor to the right and lift upward.
4. OEM one is not held in with a screw, it slides and locks in place but there is a hole for a screw if ever necessary. (like if an aftermarket one doesn't come with the slide lock).