or take the tumbler out, bring it to a locksmith and have a new key made
It's quite simple to remove the tumbler remove plastic covers, with a hammer
and small chisel break the sheer bolts loose and remove the lock assy.
Inside the threaded bolt hole in the lock assy closest to the tumbler is a
set screw (small flat blade) loosen the set screw till the tumbler pops out
make sure to look inside the lock, there is a spring behind the tumbler in the lock assy.
once the tumbler is out bring it to a locksmith or take it apart further and remove the pins