The tensioner is what puts tension on the belt you need to remove. You need to relax it first before you remove the belt otherwise the belt won't be going anywhere. I don't know specifics on the Honda V6, some other memeber can probably answer this, but most cars with a spring loaded tensioner there is a fixed point where a socket can be placed(it looks like a bolt but is not). A breaker bar and socket can be placed on that point and by attempting move the bar in the proper direction, the tensioner moves off the belt and the belt can be removed. Hope this is the case, if not, another member should be able to help you out.