retrofitting

We will be retrofitting each apartment in the complex by installing all new, stainless steel appliances and fixtures throughout the kitchens and bathrooms.

You should try to use retrofitting if possible so that you don't have to purchase a lot of new machinery.

After the gun was made it was decided that it would be more functional if they added a laser sight to it. The process of retrofitting it would be simple thanks to the design of the gun to begin with.