Yes exactly. As long as there is a mutual agreement between everyone, it is not impossible to even create new currency to be used or change the financial system in which it won't be dependent on USD. In regards to changinf currencies, we are all aware that there have been mamy issues involved with USD even from before, and there are so many countries who are already waiting to be next reserved currency.
The currency alone is easy, but the agreement is the one that seems possible. We know that before it reaches some sort of agreement, there're various procedures to follow and it is also possible that there will be debates and arguments to follow.
Perhaps the desire of the BRICS countries to get rid of the dollar is indeed there. Russia, for example, has not only a desire, but also a necessity. Because it is actually cut off from the dollar and the euro by the imposed sanctions. There has long been a cold war for economic supremacy between China and the US. But Russia, China, like the rest of the BRICS countries, depend on technology and trade with the EU and the US. And without these technologies, they will not develop rapidly. Therefore, not everything is as simple as it seems at first glance. Each member of the BRICS will still have their own interests. So I don't think they will succeed.