Given the following reaction:

3 H2(g) + N2(g) <- -> 2NH3(g) + heat

If the following changes were to occur what direction shift will it have (left or right)
And what will be the reason of the shift

Changes/Stress on system:
Decreasing the pressure
Adding heat
Removing N2

Something is missing here. You saw that answer from Sarah and I explained that part. What do you not understand about this? All you need to do is reason out the law. In fact I answered what P will do (both increase and decrease). I explained about adding NH3. Why won't the same kind of explanation work for adding heat and removing N2?