The 31-year-old has failed to reproduce the form that won him a World Player of the Year award in 2007 since he joined Real from AC Milan for a fee of 65 million euros ($86 million) in 2009.
Real have several players ahead of him in the pecking order, including Germany's Mesut Ozil and Spain's Isco, and Kaka said he hoped to move on before the transfer window closes on September 2.
"The club knows I want to leave and I would like them to help me find a solution for my exit," he told reporters on Thursday after scoring two goals in a 4-0 win in a friendly at Deportivo La Coruna.
"Things are difficult for me here, there is less room in the squad all the time," he added.
"I am ready every day to train and work but that does not mean that I am happy."
Kaka's departure is likely to be complicated by negotiations over his wages as he is one of the best paid players in the world, earning more than 10 million euros a season, according to media reports.
"I cannot go to Brazil because the market is closed, the exit would be within Europe," he said. "I don't want to talk about clubs because I have none at this stage."
($1 = 0.7562 euros)
(Reporting by Iain Rogers; Editing by Sonia Oxley)
