The Model 74 is incredibly simple to take down.
Just push the large pin at the rear of the receiver to one side and the bolt will slide out the rear.
everything is in your hands from there.
If the gun has the same problem mine had ( bolt stuck, won't fire, trigger seems stuck ) try this:
You may have difficulty removing the bolt, but she'll go.
Rotate the firing pin to find the 'sweet spot' whereas the action works smoothly. Firing pin removal may be necessary (just a couple of pins).
To check it, you can perform a function check with the bolt outside of the receiver. The lever on the bottom of the bolt is engaged by the trigger, and the bolt cocks and fires outside, too.
Once everything appears to be working fine, just slide the bolt back into the receiver. You will notice that it is much easier than removal.
Load the magazine and let her rip ( at a range, of course ).
It may take a bit of trial and error, but you'll find out what's up.
If parts are needed, try Numrich Arms at
www.e-gunparts.com.
They have a complete parts breakdown and schematic, also.