Dating is the best way to tame these. The appropriate dress for the occasion is a full suit of Ghille Armor. Pick your ape date up with a Quetz, drop in a taming pen, and hand-feed Mejo Berries. He/she will love you for it!
Build a small pen with a foundation a doorway and 2 walls then get him to chase you into the foundation escape through the doorway and place the last wall behind him then add 4 more walls above then a hatch frame at the top then feed him from above
So you CAN pick it up with an Argy, I just did with mine who has a 1100 weight skill. Please upvote so others can see, this giant monkey is too useful to have and you shouldn't have to wait till you get a quetzal to easily tame one (aka pick it up and drop it in a pen)
I've found him every time walking along the beach of the redwood biome. What was mentioned earlier works, build a stone trap. One foundation 4 door frames get him to chase you in then seal it. A random sabertooth tiger showed up during my tame attacked him and reset my timer, so beware.
Build a taming pen. Walls should be doorframes. I suggest 2x6 and two high. Put a hatch frame as the ceiling. Lie down near the whole on the hatch frame ceiling and feed him as needed. Boring, but efficient. I use my normal taming pen and just add the other walls as he walks around, to box him in on one foundation. Then, I remove the walls when done.