Sure, just create a new unsub page and place the link into the footer of the email. The thing is the default will still get appended after that, so you'll have two unsub links.
So if you want to clear that up, you'll have to do a lot of setup:
- create the unsub pages you want
- create a footer snippet for each one (Alternatively, setup different Templates)
- once tested...
- you can remove the Admin > Email defaults. Be sure to save this code somewhere in case something happens. You can drop in a white dot into the html area.