Student finance application error

I applied for student finance for a mechanical engineering undergraduate course but accidentally selected that I will be on a placement during term 3. I will have a placement in the third year instead. I am aware I have to complete a co1 form but is there a way to digitally upload this, or make a change without sending a physical letter? It keeps asking me for evidence that I will be on a placement year, and they can't proceed without the evidence.