No. The Landing account is specific per currency. You cannot change it but you can simply create New Landing account in any available currency (USD/EUR/GBP/RUB/PLN)
and then submit request for currency conversion (Transfers / Internal Transfer) or simply fund your New Landing Account with your desired currency.
See: Documents section/ Broker Forms for conversion fee.
You will be able to create MT5 Trading Account as well in new currency simply by selecting e.g..