You don't need to dig it out, but you should mix it in with the upper layers or add some dry bedding to it. I've noticed that sometimes my worms will actually gravitate to the stinky layer at the bottom (if there is one). But if you're not careful, sometimes those bottom layers will suddenly start to condense, making it impossible for air to get in and killing your worms. If you simply mix it up it should stop stinking within a few days.

Agreeing here, and just adding one more item: Since the stinky mess at the bottom does not allow air to flow through it, it will break down very slowly.

Thanks for the quick responses. Was hoping to be able to ignore it, but I guess I'll take the advice and mix it up with some bedding.

If the bottom of your bin is stinky, it sounds like it is anaerobic. (lacking air and too wet) You need to mix in some DRY shredded cardboard or (less preferable) DRY shredded newspaper.