Germany gives Euros to the Bank of Russia to buy Rubles, then uses those Rubles at Gazprombank to buy Oil.
Or
Option 2:
Germany gives Euros to GazpromBank, GazpromBank buys Rubles from the Bank of Russia with those Euros, and gives Germany the Oil.
Or
Option 3:
Germany gives Rubles to GazpromBank, GazpromBank gives Germany the Oil.
In all cases:
Note that Option 3 assumes that the Germans have already brought Rubles with Euros and have stored them.
Right now I guess the Germans do not store Rubles. But if Rubles become a rising store of value then this may change. This is the situation that Putin seeks to achieve.
An objective analysis of the meaning of the news release.
Only time will tell.
The one thing I am sure of is this will have significant effect on the worldwide commodity market.