1. You can use 000 steel wool to remove the loose stuff.
2. Follow by Naval jelly...wear hand/eye protection
3. Further follow by a fine wire wheel...better and more controlable on a bench grinder than a hand drill.
4. Clean well...air/cloth...not water
5. Use a rust inhibitor (Lowes, Home Depot, local hardware) and you should be good to go.
All the above applies if you are using the club as a playing club, not an antique.