Upgrading or remodeling your home might require more money than you initially estimated, which means that you will have to either recalculate everything, or figure out a way to borrow money without going into too much debt. You have to make a plan of what is important to renovate and to remodel immediately, so that you can leave the ones which are more complicated to be done another time, when you have more time and money on your hand; but you can also do the renovations on a step-by-step basis, which might save you some money in the long run.
Preferably use money if you can
For major remodeling projects, it is always better to use cash, and to pay everything at once, as you might get a discount or even a better deal. Although it will require you to pay a large lump sum, but you will have a clear head and you know you have paid for everything, so that you do not have to worry about it until it is finished. However, make sure that you save up enough money to account for eventual extra expenses as well.