I'm not a yank, but OP here raises a question indigenous people in Australia face too. Indigenous Australians represent a grand total of... 3.3% of the entire population of the 25 million people here. Barely even 800,000 total, and that's across some 200+ different indigenous nations (some of which have been completely wiped out - Tasmanians, for example).
While decolonisation is, of course, a viable goal that should be strived towards, in Countries like Australia and America and Canada doing so would be incredibly difficult - simply handing over the reins of power from da ebil wiypepo to the indigenous people isn't actually going to do anything. For starters, obviously decolonisation is impossible under capitalism. It could only be achieved through communist revolt or national collapse, which I'm sure this board would agree could strike America at some point in the next decade - Australia could be vulnerable at some point in this century, particularly with climate change. Even if America's liberals went into full white saviour complex and handed over power solely to indigenous people - what's to stop white people form forming their own ethnostate? The same could happen in Australia, too. Population demographics have been so totally and absolutely fucked by a*glos that, as OP said, some kind of decolonisation, like what was in Algeria or South Africa, is not viable in Australia or America or anywhere like that. So, to ask the same question as Lenin - what is to be done?
Let's suppose that Australia or America or Canada - we'll use Australia because it's the one I'm the most familiar with - was suddenly overcome with Communist revolt and a brand new socialist state enters the world stage. Aside from all the other shit needed to be sorted out, what do we do?
Having our rulers be chosen solely on a racial basis is dumb as fuck, that goes without saying. We shouldn't bar non-indigenous Australians from government, that's just not practical. The first step we should do is acknowledge that colonialism was a part of Australia's history: specifically, it was a bloody and brutal part of our history that resulted in the deaths of hundreds of thousands of innocent people through depraved methods of torture, overwork, execution and even outright murder. Hence, it goes without saying that the process of decolonisation involves tearing down monuments to anyone who perpetuated or participated in this system of violence and bloodshed. Changing names, rewriting history books to more accurately represent history, without shying away from the more unpleasant "let's-sweep-this-under-the-rug-and-pretend-it-didn't-happen" parts, which Australian historians so like to do. Manning Clark's "A history of Australia" is a great example of a history that doesn't ignore the brutality indigenous people suffered. This should be reflected in teaching, too - history should not be biased in favour of "australia is a white christian outpost of European civilisation" or "Australia is a place where anyone can have a fair go!!!", but rather, "Australia under capitalist rule was a bloody and brutal colonial settler-state that committed untold horrors and atrocities against its inhabitants, but our Socialist future will be free of such barbarity".
Greater emphasis should be given to indigenous history and culture, and concerted efforts should be made to revive languages, stories, tribes and peoples that colonialism tried so hard to crush. Maybe a repopulation scheme could be devised? Of course, serious efforts would need to be made to improve the living standards of indigenous communities, many of which live in destitution or absolute poverty, as well as finally closing the fucking gap - "The Gap" is a term that refers to the stark contrast in quality of life standards between White and Indigenous Australians - Indigenous Australians are 11 times more likely to have a kidney failure, 45% of the indigenous population are disabled (compared to 11% whites), half of all suicides despite 3% of the population (80% of all suicides for those aged 10-24), only 66% complete year 12 compared to 91% whites, etc, etc. real horrific stuff, I know.
Ultimately, what must be acknowledged is that not all parts of colonialism can be reversed. White people, in Australia and America and Canada etc - are here to stay. Simply removing them or placing the indigenous people, despite being a minority, in charge would be counterproductive and simply not practical. Australia will be a multiethnic Oceanic nation, it has been since 1770. America, similarly, will never be able to completely restore itself to the way it was before the founding of the USA. Americans will have to do as much as they can to decolonise, but come to terms with the fact that white and native americans will simply have to learn to live together, of course, peacefully, and with respect and reverence to the original owners. Reparations and Decolonisation, but, implemented practically and peacefully.