Pit Less adapter ?

Hello all,
Been browsing for a while and have a question about my well. Need to change my pump and I want to make sure about my pit less adapter. I have never seen one like this before but I think its one i have to unlock. Do I need to stick a tool down the plastic pipe that comes to the well cap to unlock? I have read this tool can be purchased or had by flattening the end of a 1/2 in pipe. Pictures attached.

The tool that you are referring to is used with another type of pitless. This looks just like a spool type pitless that only gravity holds in place - looks like they left a short nipple and coupling already threaded into it for some reason......I'm not really sure what the black poly is, other than a pipe to pour chlorine through. I have done this to chlorinate a well with a spool pitless so you don't get the chlorine all over the threads you pull from. When I've done it, I've just stuck the pipe in the wire passage enough to get the chlorine past the device. I've never left one in though, so as not to confuse anyone trying to pull the pump.

Ok cool, hopefully easier than I thought. Looks like a tight fit and with the rust in the casing I hope it comes out smoothly.

Yours doesn't look too bad; This is a tight fit from rust....This was caused by pouring chlorine straight on top of the pitless spool and never rinsing it off.