In the left menu box "Account operations" choose "Leverage";
On the appeared page choose the account for which you want to change the leverage;
Indicate the desired leverage and click "Change".
Attention! In case you want to reduce your leverage make sure that there are no open orders on the account or
if you have open orders, make sure that you have enough funds to support margin requirements. The change of the
leverage causes the changes in the margin requirements for the open orders and in case of insufficient amount of
equity may cause stop out.