Marketpress and Paypal icon

I want substitute the Paypal express icon that appears on payment choose when client checkout, in front end.

For manual payment I can change the icon that is stored in image folder but PP’s icon is dynamic and delivered by Paypal itself (if I didn’t misunderstood) but I don’t want use that icon and need something more clear, with credit cards and some text, so have to change the way how that icon appears.

Please, can something point me in the right direction to safely change that image without create problems with gateway?

Thanks in advance.