The remaining pieces are manufacturing and transportation. Former can be hard to make clean. Latter is the question of how quickly we can develop power grids for EV or hydrogen infrastructure and rebuild rail where it is insufficient. Also clean up mass shipping.
New small block nuclear power plants are likely better than gas at filling in intermittent wind load (which is usually month spread) and can be toggled as needed.
Methane gas leaks are front loaded they don’t have long term impact as long as we quickly stop using it. In the short term it’s a problem but long term methane is effectively identical to CO2 because 1 atom of CH4 produces water and 1 atom of CO2.
If we only use 10% of the current gas, we'll only have 10% of the current methane emissions. Once solar and wind ramp up you will not need more than 10% of the current nat gas plants. There are days when the sun is not shining and the wind not blowing, but they are not that frequent.
Solar and wind electricity generation also have a huge impact; they account for 10% of the electricity generation in the US now, but 20 years ago they accounted for roughly 0. The increase of solar generation was above 20% per year each year of the last decade (except one); wind grew at maybe about 10% per year. It's not likely that they continue at the same rate, but even if they grow at only 15% and 5% per year for the next 2 decades, the impact will be huge.
We can get to a point where we only have solar, wind, hydro, nuclear and natural gas. The natural gas will be the most economic way to deal with the intermittency of solar and wind. Then we'll switch to hydrogen. Then we'll decarbonize steel and concrete. We'll actually start doing that in parallel. Once concrete is decarbonized, there's no point in wooden buildings.