No problem for a competent gunsmith.

Brownells sells an expanding choke reamer and barrel hones, but this would not be a job for the average gun owner.

Many years ago I bought a forcing cone lengthening reamer and a flexible barrel hone from Brownells. I then lengthened the forcing cones in my Browning Citori trap and skeet shotgun, my BT-99 trap shotgun, and one or two other shotguns that I have. The work finished perfectly, and I have since shot over 100,000 shells through each of those Browning shotguns.