The authority of the trustee can be used to sell any item of the trust. The respective transfer documents can be signed by the trustee of the living trust. The property can be transferred to anyone. That includes a retransfer of trust property to the grantor(s).
 
The transfer out of the trust basically follows the same process as the adding of property. Therefore the aforementioned information regarding the transfer of certain kind of assets applies here as well.

If you have a shared living trust, often both trustees have the authority to transfer shared- ownership property without consent of the other trustee. However potential buyers often require both signatures if an item is sold out of a shared trust, even though technically only one signature is required. In the contrary individual property (property that belonged only to one of the co-grantors before it was put into the trust) can generally not be controlled or transferred by the other one.

The transferred property should be taken of the property schedule after the transfer. This avoids confusion of the successor trustee upon death of the grantor.