Thank you Al, you saved me from having to scrap cheese out of the mold.
I actually pressed without sanding the insert the first 30 minutes but since it was still soft so it came out from the mold unscathed with some encouragements (bashing the bottom of the mold and loosening it with fingers and other poking device). Then I found out from you (thank you again) that I have to sand the insert.
At midnight my mind wasn't very clear and I was desperate so I went for my vegetable peeler, and....it worked! Phew...
This morning it came out of the mold like a dream, it is still in the brine now. I will put up my make in a separate post.