Inspect the entire surface over which you want to apply a fresh layer of stucco. Remove the soft parts of stucco by pressing with your bare hands. Use an iron brush to scratch the old layer of stucco. Remove dust and weak parts of stucco from the wall.
Sprinkle the wall with water to soften the old stucco layer so that it becomes attachable to the new stucco. You can use a grinder to remove the high or obvious spots in the wall. The rule of thumb is that no points should extend more than a quarter of an inch than the shallowest dents in the stucco.
Give the wall one night to completely dry out. Get a concrete bonding agent from the hardware store and apply it on the wall thoroughly with the help of a used or worn out paint brush. The purpose of this bonding agent is to restrict transfer of moisture from the new stucco layer to the previous one to prevent seepage.
Prepare a mixture of stucco according to the given instructions. Add less water initially and mix it well using a shovel. The stucco should be in the form of a thick paste and should not be too soft.
Use a trowel to apply about a quarter of an inch coat on the wall. Move the trowel in semi circles and push it hard to make sure it is attached to the wall properly. Some stucco may fall during the process and there is no harm in collecting it and adding it back to the stucco mixture.
Give it about 20 minutes to harden and then apply scratches on it with the help of a hard broom. Give it a one day break.
Prepare a fresh mixture of stucco and repeat the last step again with the only difference being that you should use a metal trowel this time around, as it will give stucco a smooth finished look.