The SFX process is one you kind of just have to figure out. Go to their deposit a week page and start the process, click on the drop down for resorts you own and select add a resort to see which ones they take that you can book. Typically I wind up using Wyndham resorts in Florida; they'll take Hawaii, too, but those cost more. Once you've picked one out, check the calendar to see what they consider a high demand season week that will get you some bonuses, pick the week, book it in Wyndham and go through the deposit process with SFX. When you get the deposit form to sign, sign it and email the Wyndham confirmation email to SFX (I usually use both their catch all email and Anne Fleming <firstname.lastname@example.org
>; she seems to be the one that typically deals with deposits, at least for me).
Once you have the week deposited and they've acknowledged it, keep an eye on Wyndham for discounts that pop up now and then. SFX doesn't care if you cancel a week you have deposited with it and substitute a rebooked one you got for a lower point cost - Wyndham refuses to work with them and confirm deposits, so it's pretty much an honor system where you will eventually get an email from SFX asking you to add a guest name to the reservation. Because Wyndham snubs the smaller exchanges, those exchanges that will accept Wyndham deposits don't care if it's the same confirmation number the guest uses as the one you deposited originally. Occasionally I get a few thousand points or so back by doing that; doesn't hurt having them back, but I only deposit there when I'm not using all my Wyndham points in a year anyway, so I may wind up dumping some in RCI at the end of the year anyway. About every other year I get a certificate for a free week at Buganvilias as a bonus for a deposit, too. I know some people don't like SFX much, but if you like going to Mexico, they're a good one to know how to use.