Krell KSA 300 S power conversion

I have a Krell Ksa 300s and i want to convert power from 110v to 220v. Can someone help me out,please.I appreciate your help.Thanks.
You cannot - at least not in a lasting way. There is a card in the front panel which you need to swap out and change for the appropriate voltage.

If you use the existing one but do some modification, it will power up but then will give you problems in the long run.

Hope this helps.