Select a team in Career mode. Purchase a player who is listed for loan.
Sign the player, then go to "Budget Allocation", and set the "Transfer
Funds " to "Wage Budget" ratio 0:100. This makes the money for
transfer funds 0%. Go to "Sell Players", and terminate the loan of the
player you just signed. You should have more than $2 billion. Go to
"Budget Allocation", and change your wages funds percentage as desired
(40:60 is recommended).