electric, or crank? either case you're going to have to undo the arm rest bolts, and snap the 'christmas tree' fasteners off, push up, take the panel off and see that it has come off of it's track. take a look to see what's cracked and needs replacement, as these things just don't happen by themselves and need a bit of poetry in plastic, that can be easily replaced.
Easy common VW problem, Bob is correct^
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Hector Irizarry Duval