WELL first and foremost congrats on scaling the first hurdle and i think you are gonna face the hardest and most sensitive step(aint tryn to scare you,just being realistic).I believe anybody with proper practice can scale an aptitude test but not everybody can pass an interview.
I wont bore you too much with the hulabaloo of the dos and dnts of an interview,i will only tell you to be yourself,confident,honest and well composed.
Do not show even one iota of nervousness(though its natural),try and go tru your resume,make sure all that you have in it are wat you can summarise in not more than five sentences(do not repeat your resume)
On the day of the interview,wake up early,pray to God and be there at least 30 mins to the time,dress appropriately(black suit,white shirt,blue/red or cream tie and black shoes)
Pls of course you need to do some research on the bank so as to be well armed with info.
Pls be confident,keep eye contact and smile often,sit up st