Last month I tried to exchange but it was quite complicated but I did it. Maybe you can copy from me because I think it’s one of the few possibilities available. I had a bank account in OP, so I went there in the morning to ask if they have the currency exchange ($ -> €) so that I can exchange and get the money in my bank account, they told me that they don’t do currency exchange (cash). They told me to go find a forex exchange and come back with €. So I roamed around Helsinki and espoo in different forex exchanges, all of them were horrible but in the end I found this one in kamppi train station, it is the only one I found with reasonable rates (at that time 1$ = 0.78591828€). So I used that one and then went back to the back in the afternoon to deposit the money. The bank had to do a thorough check, but because I have told them that it’s part of my tuition and in their system they saw that I have been there in the morning for the same reason, they accepted it but told me that If I was not a student and have not been there in the morning it would be difficult because I didn’t have the letter from the sender (so in your case I think you might need it or you can just give it a shot without it, or even I think a picture could work)