AK74 bolt reassembly
What are the tricks of AK74 bolt ressembly
I am having problems with the extractor and retaining pin'
Cannot compress the extractor spring sufficiently to insert the retaining pin.
Tips and tricks?

If you can't compress the spring enough, something is either wrong with the part or with you.  It's just thumb pressure.  No big deal.

If you are compressing the spring enough, but can't get the pin in, try to insert the pin in the extractor outside the bolt, just to make sure the hole isn't burred.

Holding the extractor in with your thumb, try needle nose pliers to hold the pin, and jiggle the extractor asyou push in the pin - helps it find the happy spot.  Once it grabs, twist the pin so the cut faces 15 degrees shy of where it needs to be for the firing pin retaining pin.  When you tap it with a punch to get it all the way in, it has a tendency to rotate clockwise.  Also, if it is short of alignment, it will self center when you introduce the firing pin retaining pin.  If it is past alignment, you cannot introduce the fp retaining pin.