changing from 220v to 120v


There are a pair of Bryston monoblocks I am interested in that are 220v. The dealer says he can change them to 120v before shipping. I know next to nothing about electricity. Is the conversion easy to do correctly and well? Or migth there be non-trivial issues involved?

thanks for your thoughts.
tanglewood
Thanks for the response.  Do you know whether Bryston builds their amps for easy conversion?
Do you know whether Bryston builds their amps for easy conversion?
If the dealer is doing it, without sending it back to Bryston, then it’s easy.
"Could" even be an internal switch, or soldered bridging pads
Cheers George
I know nothing about the internals of Bryston, but it's often just spades on a terminal block.  Takes a phillips head screwdriver and voila. :)