When installing a collapsible Stock, do I have to remove the buffer tube? If so, how may I do this? On mine there is a lever to extend or contract  the size.  There is a screw that attaches to the lever and it is pinned. I have the Rock River Arms 6 position stock in CAR size. Must I remove the pinned screw, attached  the buffer, then assemble the stock, or put the whole thing together as one piece?

I just pull the lever away from the stock till it clears and will pull off the back of the tube. Also sometimes I just pull the part of the lever you use to move the stock instead of compressing it.

j3 is correct. But to clarify, you can pull down on just the pin that hold the lever in place

Knob shown here protruding beneath the adjustment lever on the bottom 2 samples and missing from 1st (Magpul photo)




Note: you need to really pull on it beyond what you think is sufficient as the last bit clears it from the adjustment holes

You can leave the stock on the buffer tube as you thread it into the lower receiver during installation, if you choose.

Or you can remove it by grasping the lever on both sides of the pin, pulling straight down, then sliding the stock off the tube.

Thanks to all who replied. While holding the lever pin away I was able to remove it towards the butt end.  You guys are too much!