Rear sprocket mounting problem

Hi there I have a trek 6700 my rear hub has a large flange that the sprocket will not fit over. I know that you can make the hole bigger will it be safe because the flange then reduces to normal. I just don't know if the extra play in the sprocket after going over the flange will make the sprocket shift with that extra play at higher speeds. If there is any solutions I would love to know thanks.

Brandon f

Thanks for your help I'm gonna check it out