It's really not as difficult as some make it out to be. You just have to learn the trick.
Once dissassembled and cleaned, put the bolt back in and put the big pin thru the hole in the bolt, turn the gun upside down, ensure the link bar is pointing towards the little socket (looks like an inverted BB), push in the assembly, and flip up the takedown bar. DING we have a winner.
The trick is the have the gun upside down after you put the bolt in. I can pretty much do it with my eyes closed now.
They are great pistols, I own an original Red label and a 22/45 bull barrel.