anyone change their drive belt? how accessible is it, looks like some of the interior plastic might interfere with cover removal?   

I'm in the process of changing mine right now.  I took off the centre plastic panel inside (partly to ease access to the front clutch cover bolts, but I also had to replace an exhaust gasket that requires pulling the front header off), and took the battery cover off too.  Once you do that it's easy to get at the clutch cover to get it off, but now I'm stuck wondering how to get the belt off without pulling the clutches.  Not a ton of room to work with in there.  Hopefully someone who has changed a 1000 belt will chime in!

[2015 Z Force 800 53/Trail EPS]

I'm in the process of changing mine right now.  I took off the centre plastic panel inside (partly to ease access to the front clutch cover bolts, but I also had to replace an exhaust gasket that requires pulling the front header off), and took the battery cover off too.  Once you do that it's easy to get at the clutch cover to get it off, but now I'm stuck wondering how to get the belt off without pulling the clutches.  Not a ton of room to work with in there.  Hopefully someone who has changed a 1000 belt will chime in!

If expanding the secondary with the bolt doesn't give you enough room between the case and the clutch to slip the belt past then the secondary will have to come loose.

If expanding the secondary with the bolt doesn't give you enough room between the case and the clutch to slip the belt past then the secondary will have to come loose.

Do I need to loosen the clutch nut or anything?  Or just thread an M6 bolt into that hole until the sheave spreads?  I assume the inner sheave on the secondary is the one that moves?  I'm hoping it gives the belt enough play to pull off the primary first, like a snowmobile?

Got it off.  Used an M6x80 bolt (closest size I had over 40).  Only 1 of the small holes is threaded.  It's a little tight to get off the primary but pretty easily doable.  Just enough room around the secondary clutch to get the belt off after its off the primary.  Belt still looks to be in great shape after 4100km but it was squaking on takeoff for a while now.  Sorry to kinda hijack your thread zrider, but hope this helps!

[2015 Z Force 800 53/Trail EPS]

If expanding the secondary with the bolt doesn't give you enough room between the case and the clutch to slip the belt past then the secondary will have to come loose.

Do I need to loosen the clutch nut or anything?  Or just thread an M6 bolt into that hole until the sheave spreads?  I assume the inner sheave on the secondary is the one that moves?  I'm hoping it gives the belt enough play to pull off the primary first, like a snowmobile?

Yes, try that first.