Safest thing to do, is get a trusted buddy of yours to log on, And slowly over a period of time, X-fer gold via Trade, And then somewhat through Auction house.
You can also, Just wing it and trade 5000g, Every 2 days. That works. Or 10k. Generally blizzard wont check their In-game trades for something like this, They usually check Mail.
But other than that, There is really no safe way to launder money to another account, Sorry.