It isn't technically hard. What is hard is making it a priority. Many countries have exchanged long term competitiveness for short term gains. Decommodifying housing would impact those who made it their business.

The process itself would be a range of options. From removing undue leverage that make people buy things they can't (or don't want to) really afford so they are reliant on rising property values, to absolute government intervention. Of course the most likely would be somewhere in between. Where the government by allocating resource (whether that is building permits, land or directly with construction) competes with the market.

And this isn't really the market not functioning as such. The market is accurately pricing things like housing high because of its importance. The problem is that eventually the market will also reflect the decreased competitiveness of important things being expensive.