Simply call member services. They handle everything. You don't have to exchange a week, they'll just take your points.
You can book II rooms from 24 months to 14 days before you travel. However, if you're reserving less than 60 days before check-in, there are some special rules that apply.
The tricky part of an II exchange is finding an available exchange. Use the DVCMember web site to look through the available II resorts and pick several choices or several timeframes. This will better your chances.
Member services will be able to tell you if your request is available and how many points it will cost you. (You can't find this info on the web site.)
II bookings are for weekly trips only, and resorts usually have a restriction as to which day of the week you can check in. (Usually Fri, Sat, or Sun)
If MS doesn't find an instant match for your request during the call, they'll give you the option of going on the waiting list. Be aware, though, this will be an automatic booking if it comes through, so be prepared to travel when and where you requested.
You can't bring your points back into the
DVC system once the booking has been made. If you cancel the reservation, you need to use the exchange within II. Different rules apply to how soon before check-in you canceled as to how long your exhange credit is good.
DVC charges a $75 fee when you book an II exchange, or when you go on the waiting list.
You can also advance deposit credits into II and make a reservation up to two years later. I guess this is an option if you know you're going to use an II exchange, and have points that couldn't be banked or used in your use year, but don't know exactly where or when you want to travel with II. In this case, DVC will create an actual 7-day booking with your points and transfer it to II. There has to be a room available before the end of your use year for them to allow you to do this.