Enlarging it by 75% would actually shrink it. 100% is an exact copy, anything less is reducing. I think the problem you have is the software you've used. You really need to use a photocopier, or if your printer scans and copies use that.
Otherwise, if you want to do it manually, you can draw a grid on the original, then a large grid the size you want, and copy each square by hand.
:-)