Offseason question

How can I sign free agents during offseason? Ex. Lbj, Dwade, stat, Bosh, and other players who declined their options? I can't find those players in the free agent pool.

They most likely declined their last year option, and then accepted a new contract from their current teams

I edited their loyalty in my roster. I turned them into 0 and 1 (not loyal and somewhat loyal). Where can I find players that declined their option and other FA during the offseason? I've checked the transactions and some teams signed big names such as Boozer, Big Al.