From £30 to £120 per hour, depending where you are, plus parts.
"Basically" means there will be alterations, so maybe between an hour and a day.
If the old hole's too big, new worktop, and if you can't match it, new kitchen.
£30 to £50,000 or so, then.
There are always too many variables to give a remote quote, especially for what might be a small job.