ExP has lost my back door key  he was doing some stuff in the garden for me and took it with him for some unknown reason and has lost it. He's agreed to pay for a locksmith but he's pretty short of money (as am I) and it will take a lot of nagging and effort to get it out of him (hence ex).
Is there any way I, or he, could change the lock without the key? It had the gate key on too, which fortunately was unlocked so can access both sides iyswim. Would need to change that lock too. Estate agents don't have a spare for either.
I've heard on MN that it's quite easy, but not sure if that's only if you have the key. I like having the back door open regularly to air out the house so it's quite annoying.