Changing input voltage on multi-tap transformer - Bad Cat

[scinoz]

I've got a Bad Cat BlackCat-30 that I brought to Australia from the States. It has a multi-tap transformer and I want to change it from 120 to 240 so I can lose the stepdown box I'm using.

Is this simple and safe for me to do myself? I'm good with a soldering iron etc on guitars -- but never been inside an amp before.

Thanks!