[header] How to replace bicycle trailer bearings [title] Remove the hitch pin from the 1/2 inch (12. 7 mm) axle bolt. [title] Remove the wheel from the trailer. [title] Setting the retaining ring pliers to " external ", remove the snap ring. 
[title] Using a mallet or other heavy tool, tap out the axle bolt. [step] If wheel is asymmetrical, note carefully which side the bolt head goes into.