Al+NO3^-1-->Al(OH)4^-1+NH3

I am supposed to balance this reaction and label the reduction/oxidation reactions and oxidizing/reducting agents

I have my specific steps to solving this but when I get to step 2 I do not see how I can split these into 2 half reactions

To me it seems that Al-->Al but NO3-1 gets split up into NO3-1-->OH4^-+NH3

is this right? what would NO'3 agent be?