I have a CIR M3 splicer and the blade is old and out of shape. I've purchased a replacement blade but i'm falling at the first hurdle trying to fit it. I've followed the instructions for the 35mm version here: http://www.film-tech.com/warehouse/manuals/CIRSPLICER.pdf but when I unscrew the knurled nuts to remove the lever axis there is a bar running through that does not want to budge. Am I following the wrong instructions? Can anyone help?