Hi Lou14, and a big warm welcome to the forum.
To tighten the blade correctly, you place a metal rod or screw driver through the hole on the blade guard (you can see the hole in the pic on mine above in my post)and out the other side of the outer blade guard which will arrest the blade whilst you tighten the nut....Don't forget to replce the split-pin after.
The Parts list and manual for the Victa Tilt -A -Cut are available in the Parts and Manuals topic after subscription. Just click on "My Stuff" in the top toolbar, scroll down to "Subscriptions" and follow instructions.
Also, why not drop into chat and say hi, we're often on line after 8pm.