Tank Sludge.

My tank had some sludge in it. I have two filters inline one metal and one clear.

I let the car sit for a year (problems) and now I have two clogged filters and a nasty carb now. Those are easy enought to fix but what do I do about the tank?

where do I take it too get cleaned or is it something I can do myself? If do take it in anyone have a cost estimate?