Unable to remove the blade

I removed the pin which is supposed to hold the blade (to put the blade of my former plip instead).
And then impossible to remove the blade of the key received: I was fine draw, the blade did not move and when I wanted to go the whole witha clamp the metal part that ended up separating from the plastic housing (after that commme know anyone who has ever tried, the case is good to throw).
Short to avoid unless you intend to directly resize the blade but one wonders in this case what is the point of buying a cheap housing to avoid the prohibitive replacement costs proposed by Citroen ...