Not used this type before but to remove wire I am pretty sure you would stick a small flat head screwdriver (power off of course) into the tiny rectangle with shiny metal in them. The termination block looks to be push fit. Solid core wire would be best. Stranded cable could give you a hard time. If you are using stranded wire try putting the screw into the shiny metal rectangles as you insert the wire.
Hope this helps.
Cheers,
Will