Okayyy, I felt so pumped today when I finished addressing my last set of invitations, then I had a pretty sizeable collection of stamps left over when I knew I had ordered just enough....I realized I forgot to put stamps on the response card envelopes. Every last one is sealed so do y'all know of a way I can open the outer envelopes without tearing them so that I can add the stamps and then tape them closed (using double sided tape on the inside)? Ugh, I feel like such an idiot....and I really don't want to have to buy all new envelopes, all new stamps, and start all over. help please

thanks