Follow the steps below to reactivate a Practice.
Select Customer Setup > Practices.
Place a check in the Include inactive practices box to include inactive practices in your search results.
Use the Show All button to view all practices. Or use the Search field to further drill down your search.
Select the Practice to reactivate.
A pop-up will appear indicating "This practice is currently inactive". Click OK.
Uncheck the Make this practice inactive box.