The quick way is strap extenders. Little belts (6" to 8" long) that extend the existing straps. It will give you a bit of breathing space to "de-fluff".

If de-fluffing is not possible then moving the buckle on the right hand side and the strap on the left hand side is the next step. Not a difficult job, but a step that you might not want to take. If you do it, what is the incentive to de-fluff?

Many of our vendors here sell the extenders.

Regards

Chas