I've never used Fuji 1600, but there are several threads here on photrio, which deal with expired film in general. Add to these instructions the fact, that fast films typically age much worse than slow film. Since we don't know, how the film was stored, you're pretty much on your own here with this roll. You might well get the combination of ISO 1600 grain with a real speed of 400 or less. Or you may be lucky, the film was stored well, you you will not see much difference to fresh film.
I get you'll have to try and see what happens.