Have you seen the spindle lock button (23 in the booklet) it's on top of the motor housing,press this down rotate blade carefully,with a gloved hand untill it locks,this will allow you to tighten/slacken the blade!
Done it Dave., May 2009
I just checked mine (which is in pieces because I can't get hold of a spare part - so look after yours) and it is a reverse thread, so no wonder it is tight and getting tighter!
James, May 2009
Indeed you do, but use a good fitting spanner because you don't want to round the bolt head off. Jam the blade if you can - I use a steel rod between the teeth, then turn the blade until the rod locks on the saw frame.
