the cost of converting a 2wd to 4wd would cost too much to be practical.
other than trading it in for a 4wd, you can make due with what you've got. get some better tires and sliders/armor and you'll be able to pull off "moderate offroading" as you put it. i'm sure (since this is the 2wd section) there are plenty of 2wd xterras on this board that have personal experience wheeling and can tell you how to get the most out of your front-diff-impaired suv

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as for the snow, i don't know, maybe you could just get chains or something.
welcome to the club

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