Do small pieces.
If you decide to do a single large remodel, evaluate the buildings in your city and determine if you still want or need them Check your Inventory for any forgotten buildings.
Clear some room before you start the remodel. Delete mundane buildings. If you have excess Store Buildings store some larger SBs. The more elbow room you have and the fewer buildings to place the easier the remodel.
Decide the order if replacement,. You might find laying out the main road grid first is easier especially if you use modifiec comb technique. You may prefer placing larger buildings first.
I use three categories for buildings and try to group according to those three categories. Permanent buildings like GBs and top tier SBs are one category. Lower tier SBs and mundane 1 lane road buildings are the second category. 2 lane road mundane buildings are the third category.
I start placing the permanent buildings first on the right side of the city. Those buildings and the layout won't change any time soon.
Place the second category next to the first working towards the left. The third category,if you have any, goes on the far left. Townhall goes between the second and third categories. This wil minimize 2 lane road construction. Most small remodeling will be done in the second and third category areas,
As long as you're at ti, either leave space for buildings for Events or plan now on what buildings to store or delete for the next Event.
Good luck!