I need to find current through all the resistors.
I know how to find I3, but I dont know how to find I1,I2, and I4.

 

If you can find I3 using superposition, what is giving you problems finding the other currents using the same approach?

Perhaps if you showed YOUR attempt to solve YOUR homework, we could see where you are having problems. Just show how you got I3, if nothing else.

 

Solve the following circuits and just add currents in each branch.