Shackley said:Yup, done it frequently.
Start with a straight edge and Stanley knife for the (unrolled) blind followed by a hacksaw for the metal rod and the plastic or wooden straightener rod at the bottom.
Peel back the blind an inch or two from the rod before cutting it with the hacksaw and then stick it back in place - to avoid making a mess of the blind at the top.
Remember - measure twice - cut once! You can't stick it back together again![]()