The reason the political parts of the Minsk agreements haven't been implemented is that the security parts of them have not even begun to be implemented. The reason the security parts of Minsk have not begun to be implemented is that there are still thousands of Russian troops on Ukrainian soil, and they keep shelling the Ukrainian army.
I think the first step is to get Russia to stop doing that. The way to do that is to increase pressure on them. The reason Crimea was not part of Minsk is that the Russians refused to include that in any of these discussions. The occupation of Crimea is separate from the Minsk agreements and its de-occupation is a separate issue from the ongoing hot conflict in the east.
How to resolve this? It's not easy, but the way to resolve it is that there has to be enough pressure placed on Russia to make the cost of continuing the war in the east, continuing the occupation of Ukrainian territories in the east, and ultimately the continuing occupation of Crimea untenable for the Russian government. Probably the best way to do that is through economic means and to make those costs higher.