Its entirely possible to get the clip apart:
You need to be willing to cut the original wire though, I cut mine to splice in an extension so not an issue.
You will need:
Old credit card - Cut into slim strips small enough to fit in the little holes
Picture hanging hook pins/nails (Small enough to fit in the little holes)
Kettle, mug, spoon & water
Hammer
Small tube-maybe the end of a screwdriver that will fit in the hole where the wire comes out - the end of one of my mini screwdrivers fell out so I just used the handle section
Large steel washer - large enough for the black centre to pass through but not the external case
Electrical tape, hard tube, bench clamp etc.
Craft knife
In order to do this you need to cut the controller wire and push it into the plug itself - I stripped off the black coating too so it was easier to push in. This is the point of no return...now you really have to get this thing apart!
Boil the kettle, fill the mug and drop the plug in and submerse it for a while to heat up with the spoon as it will want to float - maybe 5min or so.
Now remove it, shake it off a little as its got water in/on and push one of the picture nails into one of the little side holes - this will open up the exterior case and allow you to slide a credit card sliver in between the external case and plug.
Remove the nail and slide another sliver of credit card in the hole all the way down, it is easier using a clear case controller as you can see where it needs to get down to in order to override the clip but there was a little 'click' when it got right down to the bottom.
On the other side push one of the nails in as you did on the other side but this one is staying and slide another in next to it to hold the case and plug apart.
Now the third little black clip on the top of the plug needs to be trimmed down a little with the craft knife through the exterior case hole - you wont notice that its trimmed once its all back together - just be careful (You could do this before the plug is warmed up)
Now slide the washer over the nails/credit card slivers/input end, put the electrical tape on a hard surface (You could use a work bench clamp opened up enough to support the washer but let the centre plug pop out), put the plug input side down supported by the washer, put your tube or small screwdriver in the wire hole and push down till its wedged in there - the remaining black wire wrap on the inside will/should protect the wires.
Tap with the tube/screwdriver with the hammer and it should just pop right out! A lot of hassle and a pain in the A but it is possible, you just need to get small nails that are enough to lift the external case but not tear it apart, be patient and you shall be rewarded.. OR just install a new cable with plug!