How to create point loads ?

Hi,

I want to create point loads on my model. 

I have variable pressure distribution on my aircraft model and I am interested in replacing the pressure on the lower surface of the model with a point load , having 1.5 times the magnitude of one existing on the upper part, in one side of the model . In short, I am interested in creating unsymmetrical load. 

How can I create point loads using RBE2/RBE3 element ?

I have no clue how to do this because I just know that I need to have RBE2/RBE3 to do this ? Is my understanding correct ?

And , is there any way I can create symmetry so that I can create the same point load in other half of the model?

Looking forward to a timely response .

Thank you.