Trying to help a friend.

I will respond in order: 1. Yes, he should absolutely engage counsel, have counsel determine what warrants are currently outstanding from which court(s) and plan to have counsel meet him at the time and place of his surrender. 2. Maybe, however let me be perfectly clear, no attorney can negotiate a reduced sentence in exchange for the surrender. Most likely the court will not even consider the case without the physical body of the person sought by the warrant being present before it. If he has been sentenced in absentia there may be little or no room for a downward modification. More information is needed to know whether or not a reduced sentence is available. Courts do not look kindly upon those who fail to appear for sentencing so this may be a tough sell. 3. It is absolutely better to surrender at the court. If he surrenders at the police station he will come to court "in custody" and will be treated as if he were captured. If he surrenders to the court the judge will know that he came in voluntarily.

I concur with the previous poster, but would add that it is very likely that despite turning himself in, your friend will be taken into custody and booked into jail. Bail will be set, usually that day or the next (depending on the day of the week he is taken into custody), at which time he can post bail or bond out.