Disco 1 Disco tailgate help

Tailgate doesn't open

Right.. it used to open via key but got fed up and bought some springs and had a crack last night.. couldn't get the new spring in and gave up.. put it back together again and got ready for work.
Went to have another go again today and realised that it doesn't open at all now.. I probably forgot to put the old spring back in.
Got a friend to have a look and basically thinks that as I put it back together that I put the door on lock.
Because when I use my central locking and open.. the door is locked but when I lock the car.. the plastic thing(pop up lock) appears to be open.

Tried fiddling and most things and nothing.

So basically how do I get it open?

Please note that the door worked perfectly fine with the key prier to trying to fix it

I did this on my first disco. Solution; I sold it with a shagged rear door! Honestly I think you just have to pull it apart again whilst sitting in the boot

Yeah but if the lock is in the locked position then how do I sort that?