Anyone with a how-to to get old blade out of keyfob? Success with fob reprogramming.

I have now successfully reprogrammed some ebay keyfobs for the Sigma M30 system on my old Outback 2004 which only came with one key.   Obviously the blades on these old keys are redundant and i would like to get them out, but can't see how without. damaging the plastic housing of the fob and risk wrecking it all.  Is there any way of getting the old blade out beyond possibly cutting or grinding it off the fobs?

I managed to get a job lot of 1 button Subaru keys from ebay and it was very quick to reprogram 2 of them to work the central locking / alarm.   I think there were 5 fobs in total in the ebay lot, so if anyone needs one let me know. or I will put them back on ebay at some stage. The first key I bought would simply not work, so returned it under ebay policy for refund then saw this lot coming up and bid for it.    I now have three working fobs and two working transponder keys,(magaed to find a mobile locksmith who did a transponder key for me - £95)  so I am content.....Would be nice to get rid of the redundant old blades though.  Thanks to the advice from here to reset the PIN code initially and progress from there, and links to the user manuals.......invaluable!!.  Local "remote key experts" said it couldn't be done and "had to go to Subaru main dealer".  Bah!