Most all of what @FranklinF posted is accurate but you do not have to be concerned with the vast majority of it since you gifted the property and did not sell it to your tenant.
Rather, you only need to tell TurboTax that you converted the property to personal use (or gifted it if the program asks) and then file a 709 with the IRS (note that TurboTax does not support Form 709).
Your tenant will take your adjusted basis or the basis will be the fair market value on the date of the gift, whichever is lower. You should provide your tenant with your basis information which would include the purchase price, cost of improvements made, and accumulated depreciation deductions.
