I have a mini Martin LXK2 and the action is ok but I would prefer it a little lower. I saw a video of a (professional) guy lowering the action of an acoustic and he took out the little white bridge and basically sanded it down on a piece of sandpaper taking a few mm off the bottom thus lowering the action height.

Is it wise to attempt this at home? I wouldn't dream of it on a more expensive guitar but mine was only $400. Is there some kind of calculation as to exactly how many mm the bridge should be lowered? Or is it just a case of taking a little height off the bridge to lower the overall action a little?

Obviously I realise it would be foolish to take too much off, but would a couple mm help overall to make the guitar a little more playable?