[Rick-sta]

I found that on the later keys for models from around 2004 or older (personally on my dads 04 plate and my 55 plate), the blade holder for your original key comes out of the old fob casing quite easily and in tact by using a pair of pliers to move the key blade side to side to loosen it out of the fob case. On earlier cars (both of my 53 plate cars) I found that the blade holder doesn't like to come out of the fob case and you end up removing the key blade with the blade holder still stuck in the fob case.

on keys where the blade holder came out with the key blade, I simply fit it straight to the new fob case. On keys where only the blade came out with the blade holder still stuck in the old fob case, I remove the new blank key blade from the new key set and used the blade holder from that.