As others mentioned it was not easy to find at first. It might have changed by now, but when I visited at the beginning of November the owner has not yet had the time to put any sort of signs (the hostel has just opened, I gather). But I found the tel no. on my booking printout and called the owner and was soon afterwards let in. So I simply advise you to take a note of the number, then it won't be any problem.
A very nice owner and newly decorated interior make for a very nice stay. I was in the hostel alone and that meant I was very comfortable! It's very clean, and while the location is not perfect, it still took me only about 11 minutes to get there from the train station. Good wifi, cozy.
I arrived earlier than the check in time, but the owner didn't make any trouble because of it; let me check in and get on my way.