Can you clarify please?
The blade slides in the fob and is separate from it.
You want to fit a new blade to your existing fob, have you changed the locks on your car? But your remote still works?
The blade is just a key that fits a lock and doesn't need re-programming....it's unlikely that it's excessively worn, nobody ever uses them!
EDIT Ah, maybe you've bought another secondhand fob and want to use it as a spare? In which case, no......Sorry..... It's a new fob for your car from the main dealer, approx. £250.00.