A choke assembly for controlling air flow into a piston of a percussion tool for downhole drilling includes a choke and a choke adapter. The choke comprises a choke body and a choke opening in the choke body for fluid to flow therethrough. The choke further includes one or more arm slots formed into the choke body between an inner wall of the choke body and an outer wall of the choke body. The one or more arm slots are designed to receive one or more arms of a choke change tool. The choke adapter has an adapter opening extending through the choke adapter. The choke is sized to fit in the adapter opening. The choke is removable from the choke adapter after the choke is inserted into the adapter opening.