buy them from central wheels.
then get a level, measure off set on both sides, record them. have few beers, re measure them again 1 hour later make sur edid it right, them out with angle grinder and cut old one soff.
that or anotherway is remove 1 spoke at a time and replace with new ones.
i relaced my wheels, took into bike shop and her spun them on tyre balancer just make sure they were runnign true