Tealc4101

My freehub has been making this ticking sound so before spring gets here I was hoping to remove it and clean everything out but after doing more searching on the web I'm thinking it might be all part of the wheel and cant come off, My bike is a 2014 Giant Talon 4 27.5. I tried a 10mm key but its to small and I don't have anything larger.

any help would be appreciated. Also any recommendations for getting old grease?

here is all the info I could get off the Giant website about my bike. I have pictures too but not allowed to attach them yet.SizesS, M, L, XLColorsBlue, RedFrameALUXX-grade aluminumForkSR Suntour XCT w/ hydraulic lockout & preload adjuster, 100mm travelShockN/AHandlebarGiant Connect XC, low rise, 31.8mmStemGiant SportSeatpostGiant Sport, 30.9mmSaddleGiant Connect, UprightPedalsMTB CagedShiftersShimano AltusFront DerailleurShimano AltusRear DerailleurShimano AceraBrakesTektro Auriga, hydraulic disc, 160mmBrake LeversTektro AurigaCassetteShimano HG31 11x34, 8-speedChainKMC Z8CranksetSR Suntour NEX, 24/34/42Bottom BracketSR Suntour CartridgeRimsGiant Alloy, double wallHubsGiant Tracker Sport, 32hSpokesStainless Steel, 14gTiresGiant Sport, 27.5x2.1