Aldi Ferrex Bandsaw (scheppach hbs261)

I purchased as others did a week or so ago. All's going well with it but how do you change the speed..... I can't figure out how to move the belt over. The manual says "Release the belt with the tension screw for belt tensioning (46)"..... What is it referring
to. Probably simple but can't see anything there to release the tension...... any help please guys